Gather materials: tiles, thin-set mortar, grout, spacers, tile cutter, trowel, level, measuring tape, sponge, bucket, waterproofing membrane, backer board, caulk
Turn off water and remove shower fixtures if needed
Remove old wall covering down to studs or sound substrate
Install cement backer board or approved shower wall board
Tape and thin-set all board seams
Apply waterproofing membrane to the entire shower wall area
Mark a level reference line for the first tile row
Measure the wall and plan tile layout to avoid small edge cuts
Dry-fit tiles and mark cut lines
Mix thin-set mortar according to instructions
Apply thin-set to a small section of wall with a notched trowel
Press tiles into the mortar with even spacing
Insert spacers between tiles
Check tiles for level and alignment as you go
Cut tiles as needed for edges, corners, and fixtures
Continue tiling upward in sections
Let the thin-set cure fully
Remove spacers after the mortar sets
Mix grout and apply it with a grout float
Force grout into the joints
Wipe excess grout from tile surfaces with a damp sponge
Let grout cure according to instructions
Apply caulk at corners, changes of plane, and around fixtures
Reinstall fixtures after everything has cured
Clean the tiled surface and inspect for gaps or defects