Sifu

To even be eligible to earn this achievement you MUST acquire at least 40 stamps to have access to the first 45 arenas. Stamps within Arenas are earned through accomplishing either time, score or age constraints within the given challenge and you can earn up to 3 stamps per arena.

Now the good news: you do NOT have to earn a stamp to have a challenge get counted as "clear": you simply need to complete the challenge without permanently dying (either by dying at age 75 or sometimes by other means such as falling off of the map).

I would still recommend trying to earn at least one stamp as by this point: the challenges will have gotten harder compared to the 25 clear achievement and you will likely have less wiggle room to "skip" stamps.

Some tips per arena type are included below:

Survival

• Don't get hit!
• Make use of attacks with avoid properties, such as Crotch Punch (reverse & regular), Duck Strike (regular) and Reverse Sweep.
• Charged Backfist is a great move to stun variants like flashkicks, bodyguards and juggernauts once you get the timing down. Use this offensively if you have the room and defensively when you need the room.
• Throws and Focus Sweeps are great for giving you some breathing room, use them if you constantly find yourself overwhelmed in a segment. Note that the focus sweep will incapacitate an enemy for 10 whole seconds so you should ensure that you optimize that time by clearing out the stage while your target is winded.

Manhunt/Time Attack

• Try to focus on insta-kill tactics: Stealth Takedowns, Throws off of ledges and the one-shot knife charge if possible. Stealth Takedowns CAN be initiated if you toss a item from afar or run up on them without them noticing..
• Use walls to your advantage and knock enemies into them to deal a bit more damage.
• Run past the targets that you don't have to eliminate, especially if they are far away from the next set of VIPs.
• Do takedowns on fodder while the VIPs are spawning in. The timer stops ticking up during takedowns but the game will continue to run normally, which will end up saving you alot of time over the course of the arena.

Scoring

• I have heard others online say that Style variation is not nearly as important to scoring as efficiency is (i.e killing enemies fast and by breaking structure as opposed to wittling down health). this is typically true to easily accomplish a 1-2 stamp clear. For 3 stamps: you will likely have to do alot of parrying, tossing and crowd control to maximize your earnings per enemy.
• You earn more points the more health an enemy has so it is beneficial to prioritize structure breaking that minimizes overall damage (for the most part this is things like parrying and throws into walls).
• It is worth attempting to maintain your score colored yellow by doing takedowns, counterattacks, and varying up your moveset instead of doing the same attacks over and over.
• Keep your multipler at 3x by avoiding, deflecting/parrying, taunting (Right on the D-pad), and not getting hit. You can also use the Calbot focus move, which instantly brings up the multiplier up by 1 (from 1x to 2x, or from 2x to 3x).
• Speaking of taunts: you can taunt and then dash away to break out of the animation while maintaining the bonus streak from the taunt. you can also parry while within the taunt.
• Similar to other arena types: if you are near a ledge: ALWAYS THROW enemies off of there, preferably when they're at full health and your score is colored yellow to maximize your points.
• Take every takedown opportunity you have: whether that's the takedown itself or a throw off of a ledge.

Capture

• The fastest capture rate occurs when no enemy is present in the area.
• For Captures that are in one location: enemies will infinitely spawn in and I would recommend trying to stun them and pushing out of the circle to buy more time at the highest capture rate (Do this with either weapon throws, breaking structure, throws against walls, etc). In some areas: it is more beneficial to leave fodder alive as eliminating alot of them will spawn advanced enemies (bodyguards/disciples). It is worth experimenting with both options in the event that you find yourself struggling to obtain a stamp however.
• For captures in multiple areas: you will have to pick and choose whether pushing around or killing enemies is more favorable. Sometimes it IS faster to just take out the enemies and use takedowns as buffers to stop timeloss.
• Takedowns, like in manhunt, will stop the timer so use those effectively to minimize your time outside of the ring when you decide that you need more breathing room.
• It helps to memorize the map layout and the order in which the capture areas spawn, to move between them faster. The timer is still ticking when you're moving between the areas, so ensure you are sprinting and climbing/parkouring, while looking for shortcuts.

Below is a a video that shows gold clears on each map so you can get an idea of how to approach each map although I should warn: Attempts at emulating the video will do little if you have not continued to hone your understanding of the games mechanics and fundamentals.