Citori hit it right. Do your homework. Get a good map of your area and find out where the water is, and farm fields in between the water. I like to use the Atlas and Gazeteer, and Google Earth is a great program to give you satelite imagery of the area. Then get out there and pound some dirt! Find out what water holds birds and start asking for permission and access. Besides being a great time in itself, fishing is a great way to scout waterfowl hunting spots.
Additionally I prepared a hunting resume/intro letter that I take with me and give to land owners. This states all your contact info, any certifications, memberships, and clubs you belong to. Also put in there your hunting experience. It sounds kind of strange but shows the land owner your are serious and reasponsible about your recreation, that you have put time and pride into it, and that you will be safe and respectful on THEIR property.
Once you get a couple of good spots go to them once a month to check it out, figure out the best place to set up your dekes, where the best cover is, best access, and so forth.
Your dekes sound pretty good, maybe throw a few Canadas in there if you guys see them out there in AZ. I am a huge fan of the 11-87, a real work horse. Kent Fast Steel is a great load, 2's and 3's are good for ducks. You can kill geese with them as long as you are patient and get them in close.