I have no city and guilds in plastering. i have been plastering for 20years you can learn as you go if you know the basic you will be fine. Don't bull s**t if you don't know ask. I live in Dorking and we have lots of plasterer's and will we will help each other when we can, if am not sure on something I will call another spreed who will help. Just hang on in their mate, times are hard at the moment but it will get better. Speak with your local plasterer's am sure once you get to them they will help you out. You need knowledge not City and Guilds as the proof is in the pudding. I know city and guild plasterer's who are not that good.
so my friend if you know the basic and you are good hang on get to know other plasterer's to help you.
Best of luck