Sleep training for babies

I’ve been reading up on this and find it difficult putting my baby to crib “drowsy but awake”. Not sure if I’m doing it correctly, but he’s quite alert and agitated after my attempts. My baby is almost 3 months old. Any mummies have tips to share? And for mummies who didn’t sleep train, did baby eventually fall asleep independently? At how old, and any tips to share as well? Thank you in advance! #firstbaby #sleeptraining #sleepdeprived