To tile a bathroom wall, start by preparing the surface and applying a tile backer board if needed. Measure and plan the layout of the tiles. Apply thin-set mortar to the wall using a notched trowel, then press the tiles into place. Use tile spacers to ensure even gaps between tiles. Once the mortar has dried, apply grout and wipe off excess. Seal the grout if required.

Prepare surface, apply mortar, set tiles, use spacers, apply grout, and seal if needed.