I have a bit of time to type if you have time to read!
Well, there are many answers..... ;D If you are accurate, you can shoot full/full like A.J. "Smoker" Smith.
It all depends on the distance that the clays are from you, how fast you get on and shoot the bird, and what presentation they are i.e. rabbit going away on edge, Battue slow and lazy @ 20 Yds, minie screaming by @ 40 Yds, do you see the belly, the dome, or the edge of the bird? You can change shells to minimize changing chokes (#9's open up fast, #7 1/2's don't spread as much, normally a faster shell will open it's pattern quicker than a slower shell, spreader wads are an option too)
On the same course I have shot at a rabbit going past me at 90*'s at maybe 7 yds, and the next shot was a 50 Yd crosser. I couldn't use the same choke for both!
I like extended chokes. a) it gives the shot column a longer parallel area to stabelize in, and b) you can easily tell what choke you have in each barrel.
Now what I say is worth what you paid for it, so here goes. Personally, I like a bit tighter choke then most, and have shoot skeet with full/full when practicing (either you're on 'em or you aren't!)
I was going to explain the why's and where's, but Briley has a couple of good charts on their website. Go to Briley Mfg.
www.briley.com/ , click on FAQ's, scroll down to the "hooked on clays" question, then look for the clickable "Choke chart" and Choke selection" that Briley has in the answer. That should tell you what you need to know. Now, you can't go by the nomenclature Cyl, Mod., etc., you really need to mike your barrel's I.D., then measure the I.D. of the choke tube. The difference will tell you what the choke really is - my Browning Invector Plus chokes typically are looser than marked (skeet is really cylinder, Improved Mod is really Mod, etc.) I have a full set of Briley Extended choke tubes plus extras (1 diffuser, 2 skeet, 2 cyl, 2 IC)
Back to Briley's chart. It's hard to read, but the shot size is down at the bottom. Another thing that you really should do is pattern your gun/chokes at the distance you plan on using the chokes (i.e. skeet is patterned @ 21 Yds, Mod, IM, Full @ 40 Yds, etc.) That is the only true way to see if the chokes are working properly, and it will give you a bit of conficence boost when you see a nicely filled out pattern that a clay cannot escape from.
If you reload, Precision Reloading has a good selection of wads that can help you taylor your dispersal rate for each shot without changing the choke too much.
Now if that's too much for ya, a shorter answer is:
Cyl w/#9's out to 25 Yds going 1200/1250 fps
IC w/#8's out to 35 Yds going just as fast.
Light Mod/Mod 35-45 Yds, #7 1/2's 1300 fps.
Anything past 45 Yds, Improved Mod/Full #7 1/2 1300 fps.
Rabbits inside of 35 Yds, IC/LM # 7 1/2, 1300 fps. Past 35 Yds, IM same shell.
The recoil doesn't bother me, and I like a faster shell, plus a full payload (1 1/8 oz of shot for the 12 ga). I figure why handicap myself with less pellets when the recoil doesn't affect my shooting?
If it's windy out, bump up the shot size by 1 on the #9's & # 8's. If you only see the edge or dome of the target, same thing. Mini's, no larger than #8's, same with Battues (out ot 45 Yds or so).
HTH,
Blue-Dot-37.5
