YOU WILL NEED: papers, a flat space. Make 4 piles: keep, scan, recycle, shred. "Keep": anything you'd grab when leaving a burning building. "Scan": anything you'd wish you'd grabbed when leaving the burning building. "Recycle": anything generic. Everything else gets shredded. The scanned stuff gets shredded afterwards.
Electronic copies take up no physical space. Keep important paperwork to one ring binder and you'll thank me next time you move.