You couldn't pick a better zone to start your "crossing experience" : there are many excellent controllers around the UK (and some not quite so .... err ... helpful), but with due deference to the other good guys, I have without exception found the ATC at Luton to be absolutely brilliant at handling VFR transits. I've requested crossings of their zone loads of times, and never once been bounced - which is more than I can say for certain others (and we all can probably name them !).
It can be very busy, so make sure you know where you are when you call, where you want to enter and exit, and make your call short, precise and confident. If you're a bit uncertain with your RT, practice the call a few times before you make it ! As to level, unless you've got a very good reason for wanting a specific level, let them decide - chances are you'll get a "route via the XX threshold not above 2400". Then just make sure you drive accurately and bobs yer firkin !
FF
