Ok here's my experience so far:
I have recently enlisted help from a History tutor, which is kinda understandable cos history is nothing if not hell. I have had amazing results with her, my grades and confidence really going up and I feel like I'm so on top of my work which is great.
I also thought it would be useful to try a French tutor. This didn't work out so well, maybe it was because French is more all over the place than history or maybe its just because I hate French, but tutoring just wasn't as good.
Overall I would say make sure you pick a good tutor and don't try to do it cheaply if you're going to do it. Very good for boosting confidence and you know that you're learning at exactly your pace and asking more questions than normal in class, which is great for getting your head around things.