Opinions on this vary greatly. For clays, I like a choke and load combination that gives me solid hits with occasional smoke.
Smoke every hit means you're possibly losing usable spread.
No smoke ever, even with a hit that busts the clay into three or five chunks, your pattern is probably a bit thin for that shot.
Adjust your choke and load until say, 1/4 to 1/3 of your hits are smoke, and watch your average rise.
On a fixed choke gun, going to a slower, lighter,load with bigger, harder pellets can work wonders.
The reverse is also true.
With tubes, you can also do the above or change the constriction.
What I use applies only to me, but it may give you some ideas.
With a load of 7.5s, 10 Points Of Constriction work for trap singles when it's cold, 15-20 POC when warmer.
Skeet demands at least 8s,8.5s or 9s with 0,5 or 10 POC.
Olympic trap where two shots can be taken at a single target, I use 15 for the first and 30 POC for those long shots on .5 Mach targets.
Chinese trap, Mongolian Wobble the same, knowing that I'm overchoked at the closer presentations with the top barrel.
Sporting Clays varies, but the most common chokes in the B gun are 10 and 15 POC.
Use these as a very loose rule of thumb. What works for you is what works for you, so get out there and hit the pattern board.
Literally.
HTH....