when you decide what and where and with what weapon you wish to hunt. it may be easier for those on this site to answer more specific questions?don't be afraid to ask,it is how one learns.
different terrain calls for different tactics. I PREFER SPOT AND STALK. get on a high point and glass. I like to glass at first and last light as this is when animals are generally moving.I am a firm believer in letting my eyes do the hiking for me. once I find an animal I wish to kill ,I MAKE A PLAN on how to stalk and kill it.
if terrain is to thick for glassing. sometimes I will just pick a ridge and walk it ,glassing every chance I GET. I like to stay high but avoid skylining myself, and go slow, no sense making a lot of noise and spooking game.remember deer and elk do make noise when they travel also but avoid letting branches drag on your clothes ,making unnatural sounds . or sounds like shells clanking in your pocket, don't let your gun clunk against your binos. all these things will alert game to your presense. whenever possible use wind to your favour. if they smell you they will skedattle.
many books have been written on hunting tactics. go read some