Tile is durable and waterproof, but it's unforgiving — it needs a solid, flat base and careful layout, because mistakes set in mortar are hard to undo. Patience in prep and layout pays off.
Prep a solid base
Tile needs a rigid, flat subfloor that won't flex, or the grout and tiles crack. That often means cement backer board or an uncoupling membrane over plywood, especially in wet areas. The surface must be clean and level.
Plan the layout
Dry-lay tiles and find the centre so cuts at the edges are balanced and you avoid thin slivers. Mark reference lines. A good layout is the difference between a professional look and an amateur one.
Set, space, and grout
Spread thinset mortar with a notched trowel, press tiles in with a slight twist, and use spacers for even joints. Check tiles are level with each other as you go. Once the mortar cures, remove spacers, grout the joints, wipe clean, and seal the grout.