Hello DA42
Judging from your nickname...am I right if I guess you are a low-timer with no commercial experience at all? Perhaps fresh out of (aviation) college?
I am sorry I do not have the tips you required (a friend of mine has though, but he has flown big Boeings for years B4 joining DHL so his approach might had been different) but if you don't mind me asking...have you been called by DHL UK itself or by Career.aero?
Best luck
DK