Sneaking up on deer:
Use the scent cover when sneaking up on any deer.

New scopes:
As you progress through the game, you will unlock better scopes.

X-ray vision:
When you complete the game the first time, you will unlock x-ray vision. Press A after you zoom in with the scope.

.44 mag revolver:
To unlock the .44 mag, start a career and complete any level's two seasons.

Attracting deer:
Get a deer feeder and a tree stand. Walk to an area with a lot of trees. Set up your tree stand and deer feeder. Get up in the tree stand, use the scent cover, then use your buck call. It may take several minutes to attract a deer. For best results, use your rifles.

Exiting tree stand safely:
When in a tree stand and you want to get out, look down at the ground first. Then, get out.