The minimum bend length for light gage sheet metal is .1875”.  Try to keep bend lengths to .250” if possible.  Smaller bend lengths require special dies and, because they can only be achieved with a small V opening, you can overtonnage the die set easier.

Remember that steel stretches.  To reduce costs, you want to put holes in the flat blank and form the part after all the holes are in the part.  If you put a hole too near the edge of a bend, the hole will stretch and deform.  Try to keep the edge of the hole closest to a bend at least 2 times the outside bend radius away from the outside edge of the bend.