Did you map the faces along the right axis? The planar mapping box has the option to map along the 3 different ones.

This site has some very good UV mapping tutorials- the rabbit one should get you going on the basics.

https://www.simplymaya.com/movie_page...html?tut_id=21

There's also a sword one and a monster head one. I found the rabbit most helpful in getting to grips with unwrapping and texturing though.

In terms of stenciling have you linked the file texture, shader and stencil together?