The more I work with my students, the more I think there’s only really one thing they need to work on: preparing their fingers as they play.
When I see students stabbing fingers everywhere, I know they’re not thinking ahead; they’re living in the moment. Which is good. But musicians have to learn to be multi-taskers. Take sight reading for example: to be really good at it you have to let your hands do their thing, look at the measure you’re currently on and scan ahead a beat or two to take in what’s coming next.
Always prepare your fingers for what’s coming next. If you do this constantly during practice, your performances will be more secure.
Two other posts on preparation:
Good right hand technique will include almost automated planting/preparation. Another thing to consider is that left hand fingers that are not in use can be prepared over the strings.