I noticed that compared to my overall body,my glutes look a bit small.(I find a full glutes look very athletic and supplement a good lower body look).Also I don't do any glute isolation as I don't have cables or bands for that.I only do squats and DL for the lower body,but personally I feel that it's my genetics that is somewhat to blame. I therefore want to know how to tackle glutes as a lagging body part wrt both performance and hypertrophy.
Your glutes will develop in proportion as you get bigger and stronger. You don't need to worry about isolating them.
At 168cm and 60kg, with a 90kg squat, you still have a long way to go. Under the assumption that you are male and under 50 years old, you should be able to add 2.5kg to your squat every workout, and add 5kg every time you deadlift. If you can't do that then either you aren't eating enough food or (less likely) you aren't getting enough rest or your exercise volume is too low.
When you weigh 65kg and are squatting 125kg, then you will clearly be able to see hypertrophy in your glutes.
Heavy squats, lunges and Pistol Squats (with added weight). You don't need more. If you increase the added weight of those exercises from time to time and always perform them with perfect execution you will see results in your glutes.
I can give you the following tips (but I am not sure if you are already doing them, sorry if you are).
Maybe you are missing an important little motion when performing them. What I mean is: when you are doing squats, and are in the upper position of the movement, you should flex your glute and stomach really hard and push your hip just a tiny bit in front.
Another tip would be: when you are squating and doing the motion from the bottom position. Focus on your glute and flex them while squating and going to the upper position. So when youre doing the bottom-to-top-motion of the squat, flex your glutes from the bottom to the top and on the top push your hip a bit in front. I think you are naturally doing that, but if not try it out. Squating needs a lot of concentration and focusing if performing it right. I hope I explained it understandable.
Glute gains are definitely depend a bit on your genetics. So you are maybe not getting the biggest ones but you can surely see some gains with patience.