I do a slight variation on the "incremental" method others have described above. The first thing I do is pick out something that I believe to be 20yds away. This distance just seems to jump out at me, since I shoot 20yds indoors in winter leagues and practice outdoors at 20 quite a bit. Once I've picked my 20yd object, I just step off in my head 5yd increments past that to the target.

A buddy of mine uses a method similiar to C903. He judges distance based on what pin he thinks he should use. After shooting a 3D target he can't even tell you what distance he shot it for. He'll say something like, "Oh, it looked like a long 2nd pin, so I held that pin a little high". The scary thing is he is a decent shot and I shot against him in several 3D shoots before we became friends and hunting partners.

So basically you need to practice and find a method that works for you. There is no substitute for getting out and shooting some 3D's, though. You'll find a method that gets you in the ballpark in no time.

Good luck ... Shockwave