Real men use 4x4 natural slate tile. Cause the difference in size and thickness will make you go jack nicholson/the shinning insane. Did my master bath shower with those little instruments of torture. Never touching less than 12 x 12 tile from now on....
We looked at some of the smaller natural stone tiles- the fact that almost all of them had broken pieces in the store turned me off
I normally use Custom and apply the primer to the floor first with a roller. http://www.custombuildingproducts.com/products/surface-preparation/self-leveling-underlayments.aspx
The best is when you use natuaral stone and it swells when it gets wet. have fun making that flat with 1/8" joints!
Been there, also just did a shower with the best 6x6 tile Lowe's sells, or so I thought. There was a huge shade variation and some of the tiles were an 1/8 inch bigger..
Quick heads up if you live in a larger sized town...a lot of the tile specific retailers have a once a year sale to discard the stuff that didn't sell in order to make room for the new styles. Our kitchen tile was $10 per SF marked down to $1 a SF. Yes you have to plan ahead but that's killer savings.
I did subway tile in our bathroom, shower with a 48" wainscoat in the rest of the bathroom, plus 1" octogon floor tiles. We bought it all on a Black Friday sale at the tile shop, saved a boat load of cash on that deal. It was before we closed on our house and they held the order in their shop for almost 2 months before I picked it up.
Bath room tile torture device. What happens when you see slate tile remnant for $1 Sq ft on CL. I have a few boxes, maybe 30sq ft, left in anyone wants some tile...
I always do small joints now 1/16-3/16" I have seen lowes/depot tiles up to a 1/4" off in size. Its all factory seconds or made for them.