I am going to tile a bathroom. Back wall is tub to ceeling 8' and side to side with off set window. Where do I start.

Start by telling us if the current walls are drywall, greenboard, wonderboard or Hardibacker.

Find center of back wall, space tiles out on either side of center to corner. Shift line left or right so that last tile in each corner is greater than 1/2 tile. It can be done. Find highest point of tub. Measure up the distance of one tile. Draw horizontal level line around walls, ends and back. Snap vertical plumb line on end walls at edge of tub. Space tiles to corner. Shift line such that last tile is not a small piece, preferably 1/2 tile or greater. Lay tiles to lines, not tub or corners. If you are laying tile to ceiling, space tiles out vertically and adjust horizontal start line so that first and last row of tiles are 1/2 tile or greater. Planning ahead is secret to avoiding little small pieces that are so frustrating.

The walls are a combination of cement board and easyboard (a lite weight material) the area around the tub is cement board and the rest of the room is easyboard.

Should I use different types of thin-set for the different wall boards I've used. What would be the best type of thin-set to use in this case. Thanks!