I've had a few requests for a step-by-step on my method of creating water, so here we go.
You will need:
aluminum foil
transparent blue cellophane
(it can be found in a party store or sometimes with gift wrap)a box to cut up;
thin cardboard like playmo boxes is bestscissors, tape, and pencil
Draw out the shape you would like your body of water to be on the cardboard. A simple shape works best, if there are to many little curves, it will be hard to cover it neatly. Then cut out the cardboard.
Lay the cardboard on a piece of aluminum foil. You will want the shinier side of the aluminum foil to be the side that shows when you finish.
Cut around the cardboard, leaving at least an inch of excess on all sides.
Now very gently crinkle your aluminum foil, being careful not to tear it, to look like waves or ripples. Then smooth it back out and lay it shiny side down.
Place the cardboard in the middle and begin wrapping the foil around it and taping it on the underside. Pull the foil fairly tight, but be careful not to pull it so hard you tear it.
When you finish, the top side should look like this:
Now cut your piece of blue cellophane, leaving a little more excess on all sides.
Wrap it around the cardboard and tape it, being sure to pull it tightly on all sides.
And here is how it will look:
It's usually best to line the edges of the water with some gravel or river stones, so that the edges of the water aren't obviously higher than the surrounding land.