I recently hosted and run an introduction to portrait painting in oils workshop at the Yardley Arts Centre. This was an enjoyable experience with some enthusiastic and willing students and some great results.
My own portrait painting in oils workshop was successful but I wanted to give a big shout out to Yardley Arts. Yardley Arts is a not-for-profit arts organisation that is really placing a focus on the arts in Northamptonshire. The spacious and light-filled centre is based at Yardley Hastings. Its range of courses covers drawing, painting, sculpture, jewellery and photography. There is even an animation workshop! Moreover, there is something for everybody with previous experience not necessary on many workshops.
I will be lucky to be running another workshop at the centre in the future, but I would recommend checking out other courses. The courses are all run by experienced artists who will help improve your skills whatever your ability. Have a look at their web site https://www.yardleyarts.org/about