All depends upon the size of the area, if you can flood it in the fall, and if you have access to equipment.
If you can grow corn or milo, they are pretty fool proof for attracting and holding birds, but you need equipment.
The easiest and most effective thing I have used is Japanese millet. You really don't need to prepare the ground, just get it in contact with the soil. Also, you don't want to plant it too early because it has a pretty short lifecycle from germination to seed.
When our duck lake dries out, we broadcast Japanese millet in late June or early July. Most of the dirt is exposed already, so we simply drag a piece of chain-link fence behind an ATV to help get it in contact with the soil.