My advice is be prepared to have to learn a lot if you want to make decent money.
if your happy to drive all over UK, work on site for £2-£3pm2 working like a dog, freezing cold fighting with site foremen about H&S and then fighting for your money, you'll Be ok with just skimming under your belt
you get out what you put in and every man and his dog are skimmers now.
the major battle on the domestic side are handymen, Jack of alls who can board and re-skim who are taking work from proper plastering outfits.
credit where credit is due iv seen some of these guys work and some aren't too bad, but obviously it brings the price down the more peopel that do it.
there is good money in rendering but I can see that being flooded in the next 5 years