hi tysfoot
if thats all you want to learn then it wont take long.
i'll try and put a time limit on what your looking for..
the drylining will be so easy you'll laugh to you self. i have done a post on it on here somewhere, were i went through it step by step. but if you can
tile then you wont have any issues. if you were doing it for say 1 week all day, then you would have all the little tips picked up for doing average size rooms in that period. its all about organisation plastering because you are dealing with the setting times so you have to know what to do and when to do it. theres alot of pressure on because when a wall starts to go off and you are losing it, then theres not much you can do. at least you can scrape the addy off the wall when tiling and go and have a break!!
skimming. i would say it will take 2-3 months to get to a very good
standard. and when i say a very good standard, i mean a faultless wall because thats what you should have mate. no cats faces, no water marks just a flat solid smooth wall, so even if you consider yourself good, then 2 months is realistic.
add another 2 months for floating out walls using screeds if you want the walls perfect.
floor screeds in sand and
cement, say 1 months practice after you've learned the above and then thats it, you have all you need.
so there you go, i am being positive for you mate. do your course, learn as much as you can practice practice practice and ask me or any of the lads on here who plaster and we'll all try and get you there as fast as possible ;0)