Lining up horizontal joints on all walls

[jonmwalton]

What is the best way to make sure your horizontal joints line up exactly when tiling around corners? When the joints are only 2mm there is no margin for error.
I'm guessing that a laser level would be best, but I just wanted to check for any 'tricks of the trade' before I buy one.

 

[lancenotalot]

Make sure that when you baton up you have nice straight timber,meet them in the corner,use a level check them,this should keep the tiles lined up,more info on setting out in gcols famous tiling sticky