You first need to see how plumb your walls are and the size of the tiles. Larger format tiles should not be in an even brick pattern, they should be offset. Smaller, brick size 3 x 6 or 3 x 4 tile can be in an even brick pattern. You need to start from the bottom or from the top, making sure that where the small tile cuts will be, are in a location on the wall that is NOT in full view when entering the space.

Jan gave good advice, though if it's your first tile experience, you may not understand.

How big are the tiles? Big tiles have a "lippage", meaning they curve a bit as they cool, in the middle, so they're not really flat. They must be laid with a max 20-30 per cent pattern in a brick lay.

With all tiles, you need to lay out your tile pattern, including grout lines/spacers, so that you don't wind up with awkward tiny slivers in the corners.

Are you doing this diy?

We did brick pattern subways in our shower (I laid them myself) and we measured the first row from the center out, to make sure the pattern in each corner would be symmetrical. You don't want to start at the left with a whole tile, and get to the right and have 1/3 of a tile. It will look weird when you're done. So measure from the center out for each wall. (Here's my subway shower surround before grout, so you can easily see the layout)

I am using a professional, but he just started the bottom row, and there are tiny slivers in the corners. Looks like he is using the 50/50 offset. Tiles are 12x24.