Most of my clay shooting has been done with semi-autos where you only have one choke to play with.
Although I have experimented with chokes,and kept Nigel Teague and Chris Potter (Briley) in Range Rovers,I have never been a choke changer while on a course.
To my way of thinking I have got enough to think about studying the birds and shooting them without introducing another decision and then,afterwards,wondering whether I had chosen the right choke(s) if I shot the stand badly.
Currently I use an o/u with fixed 1/4 chokes and there isn't much I can't break if I am doing the job right.
Occasionally I feel that a tighter choke would have been beneficial,edge on going away midis for example, and if I change guns,(or should that be when!),I would probably opt for 1/2 chokes.
Interesting to note that Beretta have just introduced the Outlander semi-auto multi choke with only one choke supplied, a 1/2.
For anyone starting out I would suggest 1/4 chokes and suck it and see.
Vic.