I don't know if my spending can be considered wise or not, but so far I've always allocated 20% of my monthly income for future usage, 10% for emergency needs, 40% for monthly spending, and the rest for investment/buying stuff for entertainment. It helps that most of my income is in crypto, so I don't have to spend fees to convert fiat into crypto. On the other hand, it's harder to follow my monthly plan to a T because real life never follows your prediction at all. For example, my family got sick a few months ago, and I need to spend more than usual to buy stuff for their recovery. I spent more in those months compared to the last 6 months before that.