To grow savings, maximize the gap between what you earn and what you spend. You have far more control over spending than over income, so the lever to pull first is spending. Calling it a spending plan rather than a budget matters more than it sounds — it makes the activity directional rather than punitive. The point is not self-denial but to give every dollar a job before lifestyle absorbs it.
A spending plan answers the two questions every adult eventually has to answer in cash. The first is can I afford this? — which, properly stated, means does paying for this leave the savings target intact? The second is how much can I invest? — the residual after fixed costs, taxes, and chosen consumption. The plan also turns frugality into an engineering choice rather than a moral one: spend deliberately on the things that compound utility or wealth, and stop financing recurring purchases that return neither. Pay yourself first — automate contributions to retirement and brokerage accounts before the paycheck arrives in checking, and let your spending money come from what remains. You will adapt to the residual the same way you adapt to any other number (the hedonic treadmill runs in both directions).
Use any tracking tool that fits your workflow — the brand matters less than consistent use: