I always preach checking for coverage when tiling. Here’s a good example why, we set the shower/tub in one full row of tile but because of limitations around window casing we couldn’t get the walls perfect which led to a low spot. My previous tiles in the shower were all 100% but as we moved down the line there was a low spot under the window. It’s good practice to check your coverage every few rows to ensure you’re getting 95% in wet areas or 80 % in non wet areas. We just added a bit more thin