It is important to trowel at an angle of 45 degrees and slightly reduce the angle going up the wall, this way the adhesive will stay in contact with the wall and not run out after a few inches.
Applying adhesive to a floor
When applying adhesive on the floor, put a large pile of cement adhesive on the floor and keep the angle at a constant 45 degrees.
In both cases make sure you are left with a rib of adhesive that is full and not broken up, also make sure you scrape the surface enough to remove adhesive between the ribs so you can see the surface in between the ribs
How to get tiles on the wall.
Placing tiles on the wall should be quite an easy process if you follow the below instruction.
Put your adhesive on the wall and place your first tile on top of your level batten and move lightly in a diagonal motion about 3-4 mm away then move back, do not press hard.
Place your second tile touching the first tile then move out 3-4 mm then back until it is 2 mm from the first tile and place spacers in.
Place your third tile on top of the first tile touching then move out 2-3 mm diagonally then move back 2 mm from the first tile and place spacers in
Place your 4th tile touching both sides of 2nd and 3rd tile, move away diagonally and put a 2mm cross spacer flat in the joint and make sure it sits below the surface, then move the 4th tile back into position
How to get tiles on the floor
You should now have 4 tiles in a square block which are clean and perfectly spaced.
Just keep tiling in this sequence until you have completed the whole area to be tiled
Good quality tiling courses such as UK Pro Tiling Training give a full understanding of how to tile walls and floors correctly, working from your own bathroom simulated unit you will be fitting tiles and shaping tile around many commonly found objects in the bathroom