When cleaning porcelain tiles, avoid products that contain ammonia, bleach, and other harsh chemicals. Acid-based cleansers can damage the tile, though you can clean them with a diluted mixture of one-quarter cup white vinegar mixed with one gallon of hot water. It is important always to use a soft-bristled brush or sponge, since hard bristles and steel wool can scratch the tile.

To ensure an even and unbending surface to lay tiles on, you’ll typically need to put a subfloor under a tile floor. Fiber cement backboards are the most common choice, but using plywood is also possible. Don’t neglect this step, or you could risk water damage and grout or tiles prematurely cracking or crumbling, especially in an area with high foot traffic. 

You can let the tile sit without grout. Don’t panic if there’s a delay between installing the tiles and grouting. A substantial stoppage isn't a problem, provided you keep the tile surface clear of dust and debris. Also, avoid walking over less stable ungrouted floor tiles as they are more prone to premature cracking and shifting. 

When working on your bathroom floor tiling, you should always tile the floor first and then refit the toilet afterward. This has both practical and visual advantages—the tile will have a better seal, and the installation will look cleaner.

On the other hand, when you try to cut the tiles to fit around the toilet, you’re putting yourself at a disadvantage. It’s a lot more work, it’s hard to be precise, and mistakes or miscalculations can lead to future moisture damage to the tiling, grout, and subfloor.