Most of what has been suggested seems good advice, fly to other places including abroad, and try a new aircraft, but I would suggest not forgetting to keep some of the basic skills together, ideally every flight, but at least once a month do a flight where you you do a steep turn, stall and PFL then two or three circuits when you get back, after 6 months or so of doing this you will REALLY have the basics off pat. As has also been suggested an Aeros course will give you good handling skills.