Here a tile trim is fitted to a wall that is not straight, this can be difficult to overcome and so a workaround solution is demonstrated. Tiling onto a wall that is not levelled can be very trickey, hopefully this will help
by Fluffy Hedgehog
by Backyard Crafts
by drawstuffrealeasy
by Be Cozi
by Kismis craft
by mabeyguys
by banarner