To divide money better
Is there still so much left at the end of the money? I can not help you increase the money, but here is a tip on how to achieve a better classification - without the costly budget book - achieved:
Take 5 simple envelopes, an extra envelope and a small box: each envelope is labeled by the week, ie "1st week" to "5th week". The money you have available for the month will be spread over these 5 weeks (the 31st of a month falls below the 5th week). And every week, only the money for each week is spent.
At the end of an expired week, the leftover (even if it's only a few euros) is put into the extra space. As a rule, at the end of the month, a few Euros come together. From this you can buy things in stock, e.g. Shortly before a birthday ever some drinks, just before Christmas ever stamps, etc.
And most importantly, some of the leftover money comes in the box at the end of the month and it will be kept in a hard-to-reach place by the end of next month, e.g. on the cupboard (so you are not tempted to rob that in case of bottlenecks). If you then save the money for an extra request after a few months together, the box can be emptied, this will definitely promote motivation.
At first, my kids did the same with their pocket money, even though they thought it was really silly. Meanwhile, they have learned to divide the money so that they can handle it now.