In the Mists, if you ask your solicitor she may have a pro forma list of outgoings. I'm at home at the mo so can't cut & paste it, but you should think about the following:
House:
mtge/rent
contents & house insurance
council tax
gas, elec, phone, tv licence, oil, logs, coal
maintenance& repairs, cleaner, gardener if HNW, window cleaning
Groceries inc. cleaning stuff
lunches at work, coffees, odd meal out, school meals, odd meal out for children (sep. section for children)
Personal:
clothes, shoes
toiletries, makeup, beauty treatments, hair
Holidays, birthday & Xmas expenses
Work related, eg subscriptions to journals if not paid for by company, if you're in a formal job, the odd smart suit
Transport:
car payments , car tax, MOT, service repairs, petrol, public transport, parking fees
Odds & Sods:
Newspapers, magazines for self & children,
Stuff not to forget about kids:
Uniforms, play clothes, trainers, school shoes, brownies/cub uniforms, subs for football, ballet, other after school clubs, pe kit, trips away, pocket money.