I have only done tiling once but I wrote about what I did. I think the most important thing is making a side fence and then trim that perfectly square.
@mtvannan I will also tell you that you need to come up with a way to assure that your zero has not moved between tiles. I have found (and I have a belt-driven s03, so that might be why) that my ‘x’ moves a couple of hundredths of an inch … enough to create an uneven transition on straight lines that cross the tiles…which drive me nuts. I have recommended a registration method using a hole in a dead-area of the design to allow you to make sure you’re lined up perfectly before cutting the rest of the tile - if you’re interested, I’ll find the link.