I do a couple of things typically after getting a good tiled texture, all aimed at making it look like the texture doesn't repeat as often. I usually do one or multiple of the following:
1. Use the tiled floor pattern as a texture for the bevel effect in PS over a different stone texture.
2. Put a different pattern (often a cloud like one) of larger size so it doesn't line up with the first faintly over it. I do this step pretty much every time.
3. If the pattern allows for it make a copy rotate it and randomly erase parts of the top layer so that any unique sections aren't repeated as often.