dont use liquid nails as your main glue, only as a sealer on the inside if you feel necessary. use a good wood glue, like titebond 1,2 or 3, or roo-glue. i personally think using screws is bad, unless its for bracing. screws create a weak spot in the wood, especially being that mdf is **** wood anyways. i use glue, clamps and only a couple nails from my nail gun to tac in it place to clamp. glue is stronger than the wood itself. if you really want to get crazy, learn how to dado or rabbt joint. then you will almost not need bracing.