First line of defense is not to be a mouth breather, not eat onions or garlic during hunting season, lay low in the hard booze, dont smoke, dont be a mouth breather with 3 day old zombie breath and think you have it covered because, "hey its ok man, I got a chew in".....
Keep you and your clothes clean, and washed in no scent detergents, line dry, put in bags and rough em up with some baking soda. Keep em sealed, dont wear your hunting boots unless your actually walking in the woods, HUNTING.
I like to take a pine bow, or sage sprig and rub all over me and on my hat to add cover scent to myself. Puts out allot of cover scent.