Lots of good DVD's out there to improve your calling. Jump shooting on creeks or rivers, or even real small ponds can be fun too, but I prefer shooting birds with their feet down in my decoys. Nothing against jump shooting, just my personal preference.
A lot of what you're asking depends on where you're at. If you're around the big water in NWPA - Geneva, Pymy and Erie - and only have a small spread and limited experience, scouting is gonna be the ticket for you.
Find where the ducks are going when they leave the big water roosts. If you find a little marsh or swampy area that they're using off the beaten path, you're in bizniss. If you find a small enough spot that they want to be in, you won't even need decoys and calls. It could be a farm pond too. Don't overlook them. You might not see hundreds of birds like guys that hunt the big water, but if you do your homework and put some miles on your vehicle and shoes, you should get some action on mallards and other puddle ducks that are in the area.
I have a couple little puddles like this - and I do mean puddles. They're dry during the summer and fill up in the fall. Couldn't hunt them last weekend because they were still dry. But when they fill up, all I have to do is be there at first light. I put out 6-8 decoys and take my calls, but really don't need either.
This is what I look for later in the year. I really don't hunt big water, so can't give you any good advice on that. Just mostly farm ponds and little seasonal wetlands.