In article . com,
"Ed_Zep" writes:
I'd like to learn to at least skim walls pre-tiling. How difficult is
plastering to learn?

Search back on google. I've posted a few quite detailed posts on
how to plaster, as have others. You can practice skimming on a
sheet of plasterboard firmly fixed to a wall. Some unobtrusive
area such as a cupboard under the stairs or inside the garage
might also be useful areas to practice on.

--
Andrew Gabriel