We eat quite a few deer and other critters at my house...but don't subsist on it. If I had to
insure enough meat to feed my family of 4, I'd pick a gun. Thankfully I don't have to do that so I haven't hunted with a gun for about 15 years or so. I also don't have the time to hunt enough to fill my freezer with meat for an entire year...nor do I have that many freezers. I usually take at least one deer a year, sometimes more if time allows and my son usually takes one with his rifle. With the other game I shoot: hogs, javies, goat, exotics etc. we have a pretty good variety of meat to supplement our normal store-bought stuff. Hope to add a mule deer and at least one pronghorn to the larder this year :D
As far as practice, I typically try to shoot everyday my schedule allows. Sometimes it's 4-5 times a week, sometimes 1-2. Every time though, I shoot until I'm tired if light allows,if not then anywhere from 50-100 arrows.
I wish accuracy on 3D ranges or the back yard equated to that on live animals...but in my experience it doesn't. It certainly helps, but shooting fur and feather is much more difficult psychologically than foam etc. The only way I know to get better at killing critters with a stick bow is to kill critters with a stickbow...and even then, it's still not a slam dunk. But that's one of the many reasons we do this, right?