Here is a really simple one. I made a wood frame laid some Hardware cloth fencing (square holes with 1/2 inch spacing) on it a screwed the fencing down with some wood screws. I screwed down a couple of boards on top of the fencing to make sure I didn't catch an edge of the fencing with a yard tool an peal it up.
I have tried to separate dirt from rocks a few times. This setup is by far the best way that I have found. Some people go right for the water hose (as I did in my first attempt) but in my experience that is a huge mistake because as soon as the dirt turns to mud it sticks to everything, including the rocks.
Step 1: Set up the frame on some blocks
Step 2: Shovel some rock dirt mix on the screen
Step 3: Use a garden hoe to agitate the rocks and pick out sticks and garbage.
Step 4: Pull the rocks off one side and you are left with one pile of dirt and one pile of rocks.
And here is a video of the process: