I was fortunate to be invited to another art lecture at the local international school, where I used to work. The speaker was Lynne Gibson, and she gave a good talk outlining the best questions to ask yourself when looking at art. I made notes on the points and will touch on them here but I have them in my notebook and on a handout also.
I think the questions to ask when looking at art can also be turned around as the same questions to ask yourself as you are preparing your own work.
First and foremost is your personal to response to the painting. Then: Subject, form, method and context. The personal response could just be how you feel as you look at your subject, before you start to paint. The other points are all worth considering as you do your preparation for a piece. I have decided not to just repeat a list of points from the lecture but have put on here, as a record, a photo of the handout.