A budget works when it is realistic, not restrictive. Start by listing your monthly income and every fixed expense such as rent, EMIs, groceries and utilities.
Set a target for savings first, even a small one. Transferring that amount to a separate account as soon as you are paid makes saving automatic instead of an afterthought.
Track your variable spending for a few weeks to see where money actually goes. Most people find small subscriptions and impulse purchases add up quickly.
Review your budget monthly and adjust as your income or expenses change. A budget is a living plan, not a fixed rule, so be kind to yourself when you slip.