DO you separate decoys by species, keeping teal separated from mallard decoys or woodies?
One last thing, when calling ducks that are coming in, do you continue to call while circling? When do you stop?
As a couple guys pointed out, you can have the best deke set-up and the best blind set up in the world but if something is off (calling), or something is shining or reflecting the sun (ring/coffee mug/gun/etc.) none of it as a whole will matter and you'll have a tough go of it.
I hunt almost always with one other guy (and occasionally one of our kids) and what I noticed that did more benefit than anything we ever did with our deke selection or pattern was the addition of a mojo motion decoy and one feeder deke (before we got one more). C pattern is the standard....we use more of a W (or double C - imagine a C on top of another C) if we have enough time, area, and dekes out there. We always bring a few other species dekes to place a little ways away from our main spread, so holding a set pattern / design is a bit over rated for the most part. Obviously a jerk line or wobbler that can make things appear more life-like is a plus.
As far as the goose dekes, I have tried them almost within the mix and also have spread them out away from the duck deke spread and what seems to work the best is a few along the pond edge and a couple even up along the downwind bank/shore, making sure that the dekes are looking towards the duck spread. You want this to look as realistic as possible and geese will never take an eye off of anything else with a pulse in their vicinity. We rarely pack more than 6-8 geese for a duck hunt and don't always use, but do so more often than not.
Remember to leave them close enough so your shots are within shooting range. Remember to leave room for incoming ducks to land. If you are blinded and camo'd well, I'd prefer to have them committing right into my lap right at me. Some guys don't like that, that's just how I have always set up and I think that opens the vitals more where side angled shots may leave you with less opportunity and less kill zone versus cripple percentage....but to each his own. It's all about being out there and learning on the fly. Good luck guys.