Infinity Tools Corner Clamps, 4-Pack

I've never been able to hold two boards square with my bare hands while driving screws until now. These corner clamps lock the 90-degree angle tight, and the single-handle design means I can tighten one with my left hand while my right stays on the drill. Four of them for the price is a steal.

Gluing up picture frames used to be a two-person job until I got these. The clamps hold a true 90 degrees on their own, so I can set both boards, tighten, and walk away. Four in the pack means I can do a whole frame at once.

Assembling drawers used to mean fighting the boards while the glue set, but these hold a perfect 90 degrees hands-free so I can actually get the second clamp on. The 4-pack is handy since I can square up a whole box at once instead of waiting on one joint at a time.