Trial and error to see what works for you. I've done Creatine a few times and didn't feel any different tbh. I have known lots of smaller guys that really rate it though. Maybe I would benefit from doubling the dosage or something.

Plenty of protein and a good amino suppliment should be adequate. The rest is all hype and gimic imho. There are hundreds of products on the market that promise you steroid results without the use of steroids. What a load of Crap!