I often think three times before I decide to automate anything. As a dev, and co-founding with another dev, the direct response is always that it should be automated. On second thought, our billable hours are almost always better spent doing client work. This is a very relevant XKCD: https://xkcd.com/1319/

My main work (non-dev) tools are Asana and Gmail. Asana is standalone for us (looking into adding it's Timeline which seem solid). Gmail have a couple of filters.

We use a finance setup where I just forward or email my receipts and have an accountant go through it and correct all the numbers, so this is automated for our part already (we pay about $200/mo for a personal accountant to go through it).

The one thing I think we spend too much time on is support issues. Customers will mail me personally, or my colleague, and it's hard to keep track of everything. We have a small team of students doing work on this and will soon have a custom web app solution built.