Just save up enough money to be comfortable not taking any salary for the next 15 months or so. Some ways to save include but are not limited to: buying in bulk

Just save up enough money to be comfortable not taking any salary for the next 15 months or so. Some ways to save include but are not limited to: buying in bulk, skipping everything considered a perk, holidays, cooking 100% of the time (I recommend meal prep)... The problem with that is, more often than not great startups have a 12-16month window to launch. Depending on your particular instance, you might miss yours while you're saving up. A way to kinda mitigate that risk(or just an alternative way on its own) is to work all the free time on it + get some cofounders + raise a friends&family round.