Student overdraft...?

Hello,

I currently have an overdraft for £200 with a particular bank. They have promised me up to £1500 in terms of what I'm allowed, but I will need to state my case as to why I need it before they approve my request. What I want to know is, how should I make out my financial situation when I go into the branch? I have a few methods of income I could put down, but I'm unsure if I should make myself seem reliant on my student loan. Should I make myself out to seem reasonably well off, spending a fair amount on books, food, going out, etc, or shall I make myself seem relatively frugal, spending as little as possible. Either option is still very much how I live my life, but obviously it is how the bank sees my situation that will affect how eager they are to help me. Last time, I was denied an overdraft because of a payday loan that had been paid off 2 months beforehand, purely because it was on record, so you can see how sensitive their requirements are.

How would you approach this matter?
Your thoughts will be much appreciated.