Do You BackButter Your Tile?

I do lots of tile.
I think both methods work when done right.
I more often then not back butter.
On floors is where it can be fast and effective to trowel the floor.
Walls are where I find it more crucial to back butter,but there are exceptions to everything.
An experienced tile guy knows what to look for , how to prep properly and signs of good or poor adhesion.
Best of luck.
Jim