Ask HN: Startup / small business owners, how do you fill your downtime at work?

I have my own business that is doing well and offers many exciting challenges and tasks. That said, I've also done a lot of work to build infrastructure and automate/delegate my workload, and as a result, sometimes I find I don't have a pressing task to do.

It's easy to be proactive when there is an immediate thing that needs to get done (ie: prepare tax information for filing), but filling the downtime with something productive can sometimes be a little difficult. Usually that's filled doing cold-call sales for me because growth is always a priority. I'm wondering how you keep your mind, activities, and business goals fresh.

TLDR: Creating work for yourself can be hard. What do you do when your immediate work obligations are completed?