I’ve said before that hunting and having the ability to harvest game and put away food is about 90% luck and 10% skill. Skill is the part you have to control. A good portion of that skill comes from practicing your marksmanship.
I try to shoot every gun I own at least 3 times per year. I used to shoot more when I had a good deal of land at which to do so, but I still manage to find places to shoot.
The one huge drawback is that practice takes ammunition and ammunition is expensive. Checking the local gunstores has mostly been a losing proposition for me. However, the online ammunition suppliers are extremely reasonable and offer a great selection.
For my .308 I use 150 grain soft point bullets. I took a deer with these (one shot) last winter. However, the hunting loads I use are more than 20 bucks a pop. There is a cheaper solution. Though you give up a little bit in the similarity of the load you can get awful close to duplicating it with a similar choice like this one from luckygunner.com, a site I found after perusing MD Creekmore’s Survivalist Blog.net. You can’t hunt with FMJ (and wouldn’t want to) in most states but nothing prohibits you from practicing with it.
Sighting in your rifle is not a tricky proposition. This is the best method I know.
So, remember-sight in and shoot as much as possible. It gives you a feel of the rifle and shooting it in the deer (or turkey, etc.) woods will become like second nature.