Is it better to set a fixed percentage or a fixed dollar amount for taxes and savings?

For variable self-employment income, percentages almost always beat fixed dollar amounts because they scale automatically with what you earn. If you commit to setting aside, say, 25% for taxes and 15% for retirement off every payment, a big month and a small month are handled the same way — the set-asides shrink and grow with revenue, so you're never trying to pull a fixed sum out of a thin month. Fixed dollar targets work for employees with steady paychecks but break down when income swings, leaving you either short in lean months or under-saving in fat ones. The exception is your owner's pay, which you deliberately keep as a fixed amount to stabilize personal budgeting — there, consistency is the point. So: percentages for the variable claims like taxes and savings, a fixed draw for your salary. Review the percentages periodically as your situation changes.