Tile trim is available in several plastic and metallic colours and greatly improves the finish of tiling, it can be used on exposed edges of tiles to give a professional finish.
Here you can see tiles that have not had tile trim fitted
Here is the same wall with New tiles and tile trim fitted, you can see that it makes a huge difference
To mitre tile trim simply cut it in a small Mitre box and use a Junior hacksaw, remember measure twice- cut once!
The trim is simply bedded in place in some tile adhesive, if trimming tiles along a wall it is a good idea to pin the trim in place until you have enough tiles laid to support the trim fully.
Tile trim that is designed to go around a bath is similar to fit and should be mitred in the corner. This is also bedded into the tile adhesive, be sure to half fill the bath before fixing this type of trim as the bath will move slightly once filled and make sure that the gap between the bath and the wall is sealed with silicone before fitting the trim. Bed the trim in some tile adhesive and then tile over it.