All shotguns are different, so you have to put in the time (and ammo $) to pattern different chokes and loads to see which your shotgun likes best, BUT....

In my experience...

00buck needs a light modified or improved choke. Buffered buckshot seems to do better with the tighter side, even reaching down to a modified choke, standard buckshot seems to do better with improved.

#1-#3 buck I generally stick with a modified, maybe an improved modified or light full if I have it, something in the 0.700-0.710" ballpark.

#4 buck you can get about as tight as 0.680" in most 12ga's. Some guys might get lucky and get down to a .660" or .655" turkey choke, but I have had better luck with #4 buck in .680's.

T and BB can get down to the 0.660/.655's usually, but again, you'll have to pattern your shotgun to tell for certain. With the Dead Coyote load, I had holes in my patterns with a Carlson's Dead Coyote choke, measured it out at 0.660", sent it back to Carlson's, they sent me a new one that measured out at 0.680", reduced my flyers, and eliminated the holes in my patterns.