I like OneOunces idea of having you settle on one gun .....and take it to the pattern board ( to make sure it fits you ) ....and then find a certified instructor in your area ....and get a couple of lessons .../ maybe even with a video that you can keep of your stance, shot execution, follow thru ...
I'd also consider buying a good professional DVD - Bobby Fowler Jr has one that I like very much - on sporting / but there are others... Sunrise videos has a lot of them ..
I'd also suggest shooting more "Skeet" - again with your primary gun, and really work on foot position, lower body rotation, shoulders level, eye on target, head on comb ...follow thru ....etc / and see where your skeet scores are / and if they're consistent. I don't care if you shoot high or low gun - but if your scores are not consistent plus or minus one bird - then you have some fundamental issues. A Skeet field gives you the pairs / and a lot of gun movement on crossing targets - and consistency / especially the consistency that you can't get on a sporting course, since every day, the course can be very different. Keep a notebook log on your skeet scores / which stations you miss and why ... and it'll show you a trend.
Regardless of your goals in sporting --- class C, B, A, AA, Master - or if your scrores are in in the 60's, 70' or 80's ....its important to know how you did compared to the other shooters in your registered class. You can't tell much in a "hunter class" ....because a lot of good shooters, maybe class A or better - got bored in competition / and just come back in once in a while and shoot Hunter class...and you can't compare yourself to a Class A shooter, unless you are really in class A. There are sporting courses I've shot that are more of an "eye exam" than a good fair course / with tricky shots, thru the trees, etc ..... vs a better course, where a Class C shooter can shoot in the mid 60's and have some fun ( class B, A, AA are probably 5 - 8 birds better per class - with the AA guys in low 80's ) - and a few birds to seperate the big dogs from one another in Master class - that nobody else can hit without a prayer and some uncanny luck. Weather, nerves, squad mates, position you shoot on a particular station - all kinds of things can affect your scores in sporting ... In sporting - I like to shoot with guys that shoot like I do - primarily with sustained lead - but my preferred sqaud has one Master Class shooter ( who every time I watch him, I learn a little about his hold points, break points, that I didn't see ) ...and if I shoot behind him, it helps me a lot ...but I can also consult with him, before I step in. I also like a squad that has at least one shooter that is evenly matched with me in terms of talent ( or lack thereof ) so we can gague how we are doing against eachother. I like it - when station after station - if we are 1 or 2 birds apart ...it keeps us both focused and working ...to get that 1 bird edge...or shoot for a pepsi when its all done ...or something ..just to keep an edge / but a fair comparison. The Master Class shooter - can beat me with his eyes closed ...so I learn from him / but I don't try and compete with him - because I'm just not there in terms of talent or the amount of work he puts in to stay at that level...
Even with a shotgun ....if all you do is go up there ...and slap at a target ...and pour shot downrange... and don't really focus, don't work on foot postion, follow thru, etc ....your scores will go up and down 20 % ....and it'll never change unless you fix the little things ... Its a shotgun / but you can't be sloppy - or it will cost you targets. When I finally got better at sporting, was when I was shooting 200 skeet targets a week / and consistently in the mid 90's ....and then when I had a plan, every time I stepped into a station ....and I executed it / and if I missed, I knew why ...and I made a little adjustment on hold point, or break point, or where I took the first target, vs 2nd, etc ....and my scores got more consistently in the high 70's to low 80's ( not great / but I met my goals ...) ...