Practice, Practice Practice...Also, buy a 3D deer target and shoot at all angles that you can think of. Shoot form the stand you will hunt from if possible and in the clothes you will hunt in.
Scent control is vital, buy a pair of rubber boots. scent-lok clothing is great but it can be hot. Wildlife Research makesd some great soaps, anti-perspirants and scent killers. Always try to match your cover scent to the area you plan on hunting. Read as much as you can about setups etc.

It is a never ending learning experience.