Yeah, 30 minutes for £25 is all one really needs.
Don't have to have any massage at all, it's ok to just lie back and let her start on your C+B from the start.
She is also happy to let you change positions. Prone, on all fours, kneeling upright, standing are all ok with her.

Must say though, that I generally take the "massage" for the first 10 minutes or so, as I tend to ask her general day to day questions as she does.
Nothing specific, but for me it's like talking to a freind.

And I quite like the moment she stops the kneading, and I can hear her reach for the oil.

After that, I've been known to go through all positions until I decide what "mood" I'm in for the ending.
She's happy to oblige with any.
Kneeling upright, with one hand working the front and the other carressing the balls from behind is hard to beat for me.
Can even peek a look down her top. And I'm sure she pushes her mound against the side of my knee when I get closer.....