Starfield

This is currently the fastest method to farm XP in Starfield. It seems to be also a glitch so utilize until they patch it ;-)

What do you need:
1. The Coachman with Hornet Nest mod (requires "Magazine and battery mods" level 3)
2. Zoology and Planetary Habitation skills (level 1)

Travel to Pyraas System / Pyraas VIII-a. Find a desert surface, complete the scan of an animal then build an outpost with some Animal Husbandry Facilities. Build also a Four Wall Hab and place the outpost beacon on top of the hab.

Shot the generators at every building to farm XP then walk up to the beacon and enter the build mode. Tap „repair” on every facility. Rinse and repeat.

Video guide:

This can be a long process in total, but is worth it overall. I would recommend saving this to be your last achievement as you'll need a good general understanding of various game mechanics, and a decent amount of skill points.
Step 1: Prerequisites
Skills: Outpost Engineering
Research: Resource Extraction 1 & Power Generation 1
Ship: 1500-3000+ Cargo Space
Resources: Grab from Jemison Mercantile and store on ship
18 x Adaptive Frames
124 x Aluminum
24 x Beryllium
30 x Copper
2 x Fiber
99 x Iron
24 x Tungsten

Step 2: Al & Fe Farm on Andraphon
The next step is to go to the Narion System to find Sumati's moon named Andraphon. Fly there and scan the planet. You are looking for a specific place on the scan where the Aluminum and Iron resource veins meet (see video). This location is found where the mountains (iron) and craters (aluminum) meet. So land at the craters as close to the mountains as possible, and walk towards the mountains. Use your scanner and outpost builder to find a single location that can extract both. This can be tricky but is important. If you're unable to find this, you can build two separate outposts; one for each resource; and connect them with a cargo link.

Now place your outpost, place down 6 aluminum extractors and 6 iron extractors. Then place 10 solar arrays for power. Place 3 storage bins by the Al, and 3 storage bins by the Fe. Connect all the extractors to a storage bin, and then link that storage bin to the others in the group. Repeat for both extractors. Lastly, place a industrial workbench and bed.

Go to sleep, and on this moon, 1 hour of local time is equal to 6 hours of universal time, meaning you'll fast forward 140 hours in a 24 hour sleep. When you wake up, you'll have storage bins full of your resources. The first time you sleep, it's worth waking up and using you new resources to make more storage bins; not forgetting to connect them in a chain. Once you have a decent amount of storage bins (about 8-10 for each element), you can start grinding XP and levels.

Sleep for 24 hours. Wake up. Go to the Industrial Workbench, craft Adaptive Frames. Hold right on the dpad and tap RB to fill the bar as fast as possible to craft them in chunks of 99. For every 99 Adaptive Frames you craft, you'll be granted a base of 99XP, and you should be able get about 1,500+ every time you sleep. Repeat this process for as long as you want. Dispose of the adaptive frames once you're done. This is how the boosting method works.

There's a small chance your base will get attacked. If so, clear the enemies and repair anything that may be broken.

NOTE: You will get a 10% XP bonus for sleeping. Or a 15% XP bonus for sleeping with a max relationship companion. See Starcrossed achievement. You can also use certain aids to squeeze out a bit extra.

You can boost XP about 5-10 times faster by then upgrading this farm to a different version on Venus. This farm was important to do first anyways, as you'll need the resources from it for the next step.

Step 3: Ni & Co Farm on Venus
Skills (Required): Planetary Habitation 3
Skills (Recommended): Outpost Engineering 2
Research: (Recommended) Resource Extraction 2 & Manufacturing 3 (allows for large storage containers)
Resources: (bring from Andraphon)
600+ x Adaptive Frames
1000+ x Aluminum
1200+ x Iron

Venus can be found in the Sol system. Venus is a great planet for this next strategy because 1 hour of local time here is equivalent to 100 hours of universal time giving you a MASSIVE bonus to resource production. This allows you to sleep significantly less and spend much more time crafting for XP.

The strategy is the same but we'll be farming Nickel and Cobalt in order to craft Isocentered Magnets here. The base setup is almost the exact same, but Planetary Habitation Rank 3 skill will be required for the extreme environment. Fit as many extractors as you can on each vein; you can use higher level extractors if you have the research and resources available. Build 10-20+ large storage containers (or 40-80+ small) for each resource. Storage containers will probably be your limiting factor for this farm; the more the better. Link them all together as before. Sleep for 24 hours. You should wake up to ~20,000 of each resource. Craft away for XP until depleted and repeat.

Once you get the Venus base up and running, you'll be getting approximately 5,000 XP/minute, although this can be sped up with a turbo controller on Xbox, or with a mouse on the PC version. You can easily go from level 50 to level 100 in 1-2 hours.

NOTE: Doing this strategy has the potential to make your game unstable or corrupt you save. It is advised to do this last, and always keep a backup save just in case.

NOTE: Instead of dropping items on the ground to get rid of them, it can be helpful to transfer them to your ship, and then Jettison the items from your ship. This will essentially cause them to disappear potentially creating a more stable world and save.

Enjoy!

I understand that outpost building and crafting on mass is currently the quickest way to go from level 1 to 100. However, some people are finding it off putting due to how complicated, long winded and time consuming it is to setup. So I'm offering another solution, for anyone just wanting to go out and grab several levels quickly using the age old gaming tradition of just shooting stuff! I managed to go from level 20 to 30 in 1 hour using this technique.

All you'll need is a gun, a ton of ammo and a star ship to get you to a high level star system! In the video below I travel to the "Archimedes" star system (Level 75+), visit the planet of "Archimedes III" and land in a high Fauna (wildlife) location such as the "Coniferous Forest". From here set the difficulty to very easy and continually kill high level wildlife until you get the number of levels you need. As I mentioned, this isn't the quickest way to get to level 100, but with no setup costs it's certainly the quickest way to grab a few levels early on. You could then spend these perk points earnt through this method on outpost engineering to make the outpost building easier or more productive.

Remember to get the "Well Rested" buff (+10% Exp) by sleeping before leaving the ship!

This is an Xbox alternate version of this method by Kibbles.
Simple explanation: You will need to set up an outpost where there is Aluminum and Iron extractors, ideally in the same outpost but can be separate outposts and connected via a cargo link. The idea is to mass produce Adaptive frames , you can do this by spamming RB and Right on the dpad to get it to 99 asap and continue until level 100. It is a very boring a tedious method but exp wise nothing competes with this.

In depth: To start I set up an outpost on a planet with both Iron (Fe) and Aluminum (Al), for me it was on Bessel III-9 the moon of Bessel III (I am not sure if they're same for everyone so make sure to find a planet with both these resources ).
Resources needed to start:
1. Extractors: 5 Iron, 2 Tungsten and 4 Aluminum
2. Power: Wind turbine 2 Cobalt, 3 Nickel and 5 Aluminum (You can use whatever power source you like tho)
3. Storage: 6 Iron, 3 Adaptive frames and 5 Aluminum (If you want this cheaper you can setup the extractors and just make these)
4. Industrial workbench: 3 Iron and 4 Aluminum
5. Bed: 2 Fiber and 2 Aluminum
6. Cargo link: 20 Iron, 2 Beryllium, 2 Zero wire and 12 Aluminum.

How to set up the base: You will need to have the extractors set up for both Iron and Aluminum (Make as many as you can), power to keep these running, a bed to get the well rested bonus (Increase in exp for 25 min), Industrial workbench (to create the frames), cargo link on both outposts if you are using two separate outposts for the resources and last but not least a metric tonne of storage containers.

The storage containers: For this part the only limiting factor of how many adaptive frames you can make in one sitting is your storage containers. Later we will see a method that will fill these all to full asap with one rest so make as many as possible. You can make more by resting once at the base and you will have enough Aluminum and Iron to make a heap more storage crates.

Connecting the crates: To ensure the crates are used once you place them down connect them all together, to do this just press RT on a container and connect it to another. Just spam this until you're sure they're all interlinked (you will only need them to be somehow connected to each other, doesn't have to be directly to the extractor). Make sure to link your extractors to the storage containers.

Filling all your containers in one rest: To do this, simply travel to Venus and rest for 24 hours. You will see 24 hours on Venus is equal to 2400 UT. Which is more than enough to fill every container* (unless you have 1000's of containers). I did this by flying there, getting out of the pilot seat and sitting on my ship and waiting there.

The method: Sleep for 1 hour to get the well rested buff, open the workbench, press A on the adaptive frame, select Adaptive frame and make as many as you like. Unfortunately on xbox you are very limited to the amount per minute you can make compared to PC which is just absurd. The most effective way I found on xbox is to spam RB while holding Right on the dpad and Right on the left thumbstick to get to 99 asap. Yes sadly this is very tiring and annoying BUT the exp per minute is significantly faster than anything I've found. To make it slightly easier on yourself I rebound my RB button to the B button in the controller app on xbox so I can spam B instead of RB, I just found this easier.

I hope this helps, if you have any edits I should make or feedback please let me know. I think I have covered everything and if you have any questions on steps feel free to ask!

2024 working method using Husbandry’s.