Hi! I've had the same question for myself, im 175cm, 73kg. So overall I'd suggest strength training with hypertrophy & progressive overload, calorie deficit with 0.8-1.2lbs per kg of protein, enough sleep. And avoiding high saturated fatty foods. Those are at the top of my mind right now.

I’m in my 20s and looking to build lean muscle too, so far I've done strength training and maintaining 100g protein on workout days, slightly lesser on rest days. I try to keep a calorie deficit (2000 calories daily) as I notice my daily burn is around 1800-2000 (resting) and 2400-2700 (active).

Mainly my workout routines have been PPL (3-4 times a week) since February and I use Hevy to track my workouts, it's really useful to track progressive overload & we can share our workouts on the Home page with other users.

Currently I'm doing a upper/lower & push-pull-leg strength training (and some cardio/ab work 1-2 a week). How about you?