The first and most obvious one is to save up a war chest. You should have money to cover expenses to last as long as is necessary before you throw in the towel

The first and most obvious one is to save up a war chest. You should have money to cover expenses to last as long as is necessary before you throw in the towel or turn a profit. Note: It's generally better to save up the money than to have to depend on spouse because your spouse then controls the project (ie if she decides that she wont support the venture any longer, you are basically out of options). You can perform due diligence after hours [ie could the idea work out if you sunk more time into it], but its difficult to really work [and may be violating an agreement, esp if you signed a really strong assignment clause] If you have a spouse [or are in US, under 26, and have parents], you can piggy-back off of their health insurance.