It is recommended to follow the 50/30/20 rule, it is a straightforward and easy way to allocate your monthly income to the different categories as follows:
50% on needs
Needs are expenses which you find necessary for survival. E.g. Food, utilities, transportation, insurance, etc.
30% on wants
Wants are expenses which are spent on enjoyment, e.g. Holiday, Shopping, Games, Gifts, etc.
20% on savings
The final 20% should be saved up as an emergency fund for rainy days.
Other than savings and expenses, it is equally important to be on the lookout for your debts. If your total debt is less than 50% of your total assets, you are considered financially healthy.