Now that you have found the perfect spot for your new pond and have determined the size and general shape of it you can start assembling some tools. Here is a list of what you will need:
A rope, long enough to follow the entire outline of your pond,
a pick axe (if you happen to have clay in your backyard),
a flexible measuring tape,
a straight board or 2 x 4, long enough to reach across the pond,
a few friends who would love to spend their weekend digging a hole in your yard,
and enough pizza and beer to keep them motivated.