For me its in the 25-35% range, but then I've managed over a long period of time to build on the idea of living below one's means in order to have more in the end. The figure I have always used as a guiding rule is spend 80% of your income and invest the other 20%. This is 80/20 of net by the way. If you take home $1000 a month, you should only be having expenses of $800. If you live your entire life like this you will very likely have very little, if any, money problems.
You can apply this rule not just to income, but say for example you want to buy a car. You have $20,000 to spend. Start looking at cars that are $16,000 and go from there. Say you are looking for a house and you figure you can afford $220,000. Start looking at $176,000 houses.
If you apply the rule to income AND spending, you're DEFINITELY on a good track. Make it a habit...they're hard to break.