If you do a lot of flat-fee projects, it can be easy to let tracking your hours go by the wayside. It can seem like just one more thing to do. Except, in thinking that way, you’re missing out on some crucial data that can inform whether or not you need to periodically reassess your workflow, your pricing, and your hours.
Most projects I do are flat fee with add-on fees for things outside the scope of that and then hourly as needed. For an on-going project that was done exclusively by the hour, I started recording my time with a handy timer app. It got me back into the mindset of how much time goes into design. Out of habit—or curiosity—I then began tracking nearly EVERYTHING.