Marvel's Midnight Suns

Friendship level can be increased by choosing the correct answer during dialogues, completing a mission with a given character, asking characters to take them on the next mission, during training (sparring), spending time together (hangout), gifts that can be given after spending time together, and also compliments.
You can also find resting places (Haven) they are located in the location and are marked with a blue circle, you can invite the hero there after finding this place. Such places are limited and you can invite only once. I advise you not to spend Haven, since the characters can give you a task so that you invite them to this place.

It is important to consider that gifts have quality and also characters can have favorite things that give 2 times more friendship points. I recommend making a save before hangout, so as not to make a mistake with the gift, because if you give the wrong gift, then friendship will go into minus, and giving a regular gift will give you fewer points.
With Hangout, things are not so simple either, heroes have favorite places and they give more points.
Hangout opens when you reach friendship level 1.

Examples of favorite gifts for heroes are as follows:

Dr. Strange
Hangout - Meditation and Reading by the Fire
Present :
- Dealing with Difficult Coworkers
- Candle (Leather and Mahogany)

Magik
Hangout - Have a Drink and Read by the Fire
Present :
- Snack Box (World's Grossest Candy)
- A box of 1000 gummy bears (I didn't have time to write down the exact name)
- Nineteenth Century Russian Poetry
- The Uncanny X-Men #160

Niko
Hangout - Stargazing and Meditation
Present :
- Passion In The Moonlight
- Dark Beauty: A Gothic Coloring BookScarlet
- Candle (Grave Dirt)
- Runaways #1

Ghost Rider
Hangout - Pool Lounging
Present :
- Serenity: Calming Your Inner Demon
- Growing Up With Trauma
- Music Box (Blood on Blood)

Spider-Man
Hangout - Playing Video Games
Present :
- Music Box (Face it Tiger)
- Multidimensional Cyphers In Gravity Theory
- Snack Box (SNAX)

Captain Marvel
Hangout - Playing Cards and Working Out
Present :
- Candle (Jet Fuel)
- Snack Box (Fresh and Fruity)
- Burning Skies: Air Combat in WWll
- Captain Marvel #1 - 2012

Iron Man
Hangout - Reading by the Fire and Pool Lounging
Present :
- Tales of Suspense #39
- Iron Man Fanfic Anthology
- Candle (Sports Car Interior)

Blade
Hangout - Fishing
Present :
- The Unauthorized Biography of Captain Marvel
- Candle (Bone)
- Human Anatomy: Volume IV

Captain America :
Hangout - Reading (Reading by the Fire)
Present :
- Snack Box (MREs in particular)
- Premium Sketchbook
- Music Box (O Danny Boy)
- Lessons in Leadership by Lt. Col. James Rodoe

Wolverine
Hangout - Playing Cards and Have a Drink
Present :
- Snack Box (Root Beers of Canada)
- Madripoor in Pictures
- Snack Box (Meat-o-Phile)

Witch
Hangout - Reading (Reading by the Fire)
Present :
- Music Box (On the Slopes of Wundagore)
- Music Box (Transcendenal Chimes)

Based on this list, you can roughly guess what the heroes like from the other gifts.

To start giving gifts, you will need a gift shop.
His recipe can be found in the video - https://www.youtube.com/watch?v=WcBEc4qsYrw
Simple gifts can also be found around the house.
They sometimes appear on some table, on a chair or in the corner by the fireplace...

When you play a new game +, all havens are reset and you have to open them again. If you want to boost your relationships with characters, I recommend using all havens in your first playthrough, starting a new game + and using new havens on the same characters.
Since I found that when buying the maximum edition you need to knock out the trophies from the DLC, I advise you to pump up relations only with the characters from the DLC:
1. You can only compliment once a day, in the later stages of the game you can compliment 2 times in a row
2. Only one sparring per day, we do it like this: Venom, Morbius, Deadpool and Storm, maybe in a different order
3. Use shelters only on these characters, after starting a new game + all shelters are reset
4. And don't forget that every few evenings you can invite someone to a hangout and give them a gift.