Here is how the trim turned out around the door, I like to try different styles in different rooms, it doesn't all have to be the same why would it?
I have primed the base and wall to allow for better adhesion of the tiles.
This is my favorite type of paint brush, with the removeable brush as it doesn't need to be cleaned during breaks in painting, keep it baggie fresh. As you can see very well used I have a few.
You can use a laser level to mark guide lines to keep tiles straight and level. Caution , don't leave this type of level around for children to get a hold of as the laser is dangerous.
I have used a standard level to mark with pencil some straight lines that will help me to set the tiles level.