I used to scramble to pay life insurance once a year or car insurance twice, because it wasn't a bill that came due every month. Now I make a list of every bill like that, add up the estimated costs & divide by 12. I save at least that every month to cover those bills.
My list includes: life, home, and car insurance, property taxes, school taxes, estimates of federal, state, & local tax. I add eye-glasses every-other year.