My client has recently had an Electrician install some sockets, in my opinion he could have made a much better job. Any suggestions on the best way to make good without turning into a major job?
I had a similar issue recently. I ended up taking the socket front off and terminated the wires into a choc block and taped up so I could get the power back on, then knocked up a bit of left over Dry wall adhesive (sets like stone) to fill the deep holes. I then left my plasterer to skim up to the edges of the back boxes as I was having the whole wall skimmed. The fronts then screw back onto the boxes nice and neatly over the top of the plaster. I guess you could do a similar thing by filling and then apply a small amount of finish plaster to the area affected working right up to the edges of the boxes and then sand back if needed before painting. Don't take my solution as gospel though, I'm only a humble DIYer
you can also use the yoozybox http://www.yoozybox.co.uk/plasterguards think they are a couple of £ you dont have to put the sockets back on but, i got some for the same reason, fitted them after the plasterer i had made a mess of all the sockets and i had to dig them out of the wall. i then filled in the gaps up to the yoozybox skimed and re painted and then removed them