How do I build financial habits that actually stick instead of fading after a month?

Lean on systems, not willpower. The most durable habit is automation: schedule transfers to savings and investing the day after payday so the money moves before you can spend it. Start absurdly small, even one percent of income, so the change is painless, then increase it gradually over time. Attach the new behavior to something you already do, like reviewing your accounts every Sunday. Make progress visible by tracking a single number such as savings rate or net worth, since seeing it climb reinforces the behavior. Remove friction from good choices and add friction to bad ones, for example unlinking a card from impulse-shopping sites. Finally, forgive slip-ups quickly; consistency over months beats perfection for a week. Small, automated, repeated actions compound the same way your investments do.