Less is more my friend!
Unfortunately, you will come across a lot of rubbish about chip butties on the internet. In my opinion, the best way to have them is to keep them simple - buttered white bread, or what we call a breadcake in Yorkshire, you can even use margarine rather than butter. Plenty of good, thick-cut chips, and perhaps a little salt. Some add malt vinegar, or Henderson's Relish in Sheffield, a few add ketchup. Brown sauce is pretty rare in my experience, I've never even seen anyone add brown sauce to a chip butty, though I'm sure some do
Strong 'Builders Tea' or beer make good accompaniments, or some Dandelion & Burdock
I'm just having chilli, while not so secretly longing for the same! 
