I go by the formula of 1/3 on accommodation, 1/3 on bills and other expenses and 1/3 on savings. However, DH and I are not there yet but we are aiming for that.
At the moment we are paying 38.4% of our take home pay towards mortgage and have about 25% left over after all bills and groceries. The 25% is the pot for family presents, xmas, savings and any debt payments if they exist, so not a big pot at the moment. It is not ideal but when we started, our mortgage, was costing us 43%! We had a tiny deposit(hence a higher interest rate), landlord was selling our rental flat and I could not put up with move to another rental only to be given notice less than 12 months later. For us, the roof over our heads was more more important and we were willing to pay a little extra to have our own home.
If you really want this house, and that you believe it will bring you plenty of happiness and that you might forever regret not getting it, then I say go for it. You learnt to adjust your lifestyle accordingly. Whilst our mortgage payments and bills have not gone down, we have both since had several pay rises to improve things a little.
Now that we about to come to the end of our fixed rate, things are going to improve a lot more. Our house has since accrued enough equity that taking a quick look at the current interest rates, we shall have a LTV of about 70% and about £350 shave off our mortgage payments from Dec 2016.
What I am trying to say is that despite the financial limitations to enjoy nice holidays/ lots of meals out, we don't regret the move. It hasnt been as bad as we thought it would be, we took care of all our bills but didnt have much leftover for luxuries for the last 4 years.
Word of caution though, we didn't have a decent cushion of funds for when if one of us lost our jobs and so you could say we were winging it. Things have improved now with a little savings behind us, able to manage on one salary (albeit very tight). The other thing is that we do not have DCs. Maybe our approach could have been different.