The most time-consuming part of making crab rangoon is assembling the wontons, but the sooner you begin this process, the sooner you’ll finish. Start with one wonton wrapper at a time. Moisten the edges with a few drops of water, then plop a teaspoon of crab filling right in the center. Fold the wrapper to make a triangle, then pinch the points (but not the sides) of the triangle closed. Now take one side of the triangle at a time and fold the points in to the center. Pinch both points to seal, then press all along the sides to make sure the entire wonton is leak-proof.
Repeat the process until you’ve used up all the filling. You should have enough filling to fill 18 to 20 wontons.