My tile experience has been on replacement floors or over cement board. I (well, SWMBO) want to put a tile backsplash above the backsplash built into the kitchen countertop. The wall is painted (many coats) drywall, in reasonably good shape, just a few small divots through to the gypsum.
Do I have to do anything special to prep the wall beyond light sanding and cleaning? Anything special in the way of mastic/glue/mud?
Any other gotcha's I should know about before I start?
TIA, Chris