Stray even a bit when installing shelf standards, and your shelves will rock maddeningly.
woodworking technique shop tip

Fit a spacer block between the cabinet bottom and a slot near the bottom of the shelf standard. Install a shelf clip upside down in the slot, and then rest it on top of the block to position the standard while you drive in the screws or nails. Repeat for the other standards for accurate placement.
—Lance Lewis, West Newbury, Mass.