To get the most professional finish possible, measure the room in both length and width so as to find a centre point in the middle of the room. Ideally, you want to have either full tiles finish up to all walls, or if the tile size doesn’t allow all full tiles to be laid, you want at least the same size border tile around all edges butting up near the skirting boards. You want to start in the centre of the room/area and work your way outward towards the adjoining walls. It is better to have neat and equal cuts all the way around the outer edge than running down just one wall.
Decide which pattern you want to use to lay the tiles, with the 4 common methods being stackbond, herringbone, brickbond or diamond. Keep in mind at the start that, depending on whether you use a rolled/pillow edge or a rectified edge tile, the grout joints can be anywhere from 3 – 5mm wide down to only 1 – 2mm respectively. This should be considered when working out your grid lines.
Decide on your centre line (grout line) and what visual effect you want to achieve. Try to have your grout lines run from wall to wall of the area to be tiled, even if there is a drain hole through the line.
Based on the tile size and your chosen grout width, mark out grid lines on the floor with a chalk string line or a light thin permanent marker from the centre working out. Double check all lines are square to the adjoining walls. The tiles can be “shuffled” around once laid down in wet adhesive, however it’s always best to have as square as possible to start with.
Use the same principles for tiling a wall area regarding grid lines - being square and using a weighted string line will give you a good vertical line on the walls. “Dry laying” tiles is always a good way to visualise the end result before committing them to glue!