I hate these kind of questions. ...lol!
It seems like im being boxed in, having to choose one option. I use all these tactics regularly, and the very spot I hunt dictates the necessity for each method.
Your question though, says which is the most used method THAT FILLS TAGS...... hence, I had to vote tree stand. It is by far the best method to fill the tags with a bow for me. Still hunting or ground hunting, a person has lots of close range encounters, that do not end in a shot opportunity. Its easier to get busted before a shot can happen too. I still love ground hunting though, and do it a lot. Ive filled numerous tags from the ground, so im no ground hunting snob. Ive been fortunate enough, to harvest 5 deer at 3 yards and more at what would be considered close range..... The fact is, if the area permits its use, a tree stand, done correctly, gives a better chance of filling your tag. I will also say, I dont go 20ft up a tree to do it, most of my stands are 12 ft, and rarely go over 15ft. Ive had a few stands at 10ft, and was very effective for the very brushy situation. A shot from the ground would have taken a lot more work, and been way more invasive and risky in dealing with sensitive deer as I was. For me, its imperative to use all available methods.