I lay tile in all my rentals, a flip here and there and my own home. I have never used thin set underneath Durock. I usually screw the 3x5 boards down on a six inch grid, yes it over kill but it works well. Then I mix my mortar to a thickness I like (peanut butter consistency) and depending on tile size I will use a 3/8in or 1/2in notch trowel. I have never had a tile come loose or break on me once set. I use the smallest spacers I can find as well. if i am tiling a shower I don't even use spacers.
YOUR first time tiling keep a bucket of water, scraper, sponge, and a towel handy to keep the excess mortar in check, do not allow it to dry in your grout line or on the top/edges of the tile. You WILL regret it later.
No one taught me how to do it I watched some videos and went at it head strong, I will say I've learned a lot along the way but it really is a simple process. Also, doing a brick pattern with floor tile allows a little bit more error as a crooked grout line isn't as noticeable when they are spaced apart.
