Thanks to Laura for this Frugal Baby Tip!
For those of you who love to use flat nappies/diapers, but hate to fold, either when your diapers are new and unwashed, or after they have been washed and pressed very thoroughly so that the edges are not wrinkled in any way, fold the diaper to the point where you have the triangle and the square on top of one another, then using sewing pins, pin the square together, and pin the triangle together so that they don't come apart.
You may also have to pin the bit where the square and triangle meet, then sew them into position so that every time you wash, you still have the square and the triangle, then all you have to do at diaper time, (after you've removed the pins of course) is to fold thesquare into three/four as described, and voila! You still have a very flexible diaper, and you don't have to do all that folding!
How to Fold: http://borntolove.com/folding.html