1. Google Calendar. Not really "automating", but I got a big boost in productivity from assigning themes to different days, so I'm not thrashing back and forth, and I can batch up similar tasks. Of course, there are fires that screw things up, but it's generally much smoother.
2. Eliminating tasks that don't need to be done, or that I've over-engineered. I have an accountability partner, and while that has a lot to do with setting and meeting commitments, it probably has at least as much to do with eliminating pointless tasks. ("If you're trying to do X, what if you just did Y for now, and eliminated P, Q, R, S, etc?")
3. Self-serving/dog-fooding, but my own software tells me when prospects are interacting with lead magnets and proposals, and it automates most of the proposal process, so I can have more real conversations with people with fewer dials and less stress.
4. OmniFocus is great for getting tasks out of my head, showing me what I need to do, handling recurring tasks, etc. I'm not really using all the functionality to the max, and I should really do a more rigorous job with reviews, but it's super helpful. (I imagine other task managers have similar features, although this seems to work best for me.)
5. Automating customer support-- there are some customer support functions that require human intervention on the back end. If something comes up repeatedly, I write a script to automate it. Not a huge time savings, but instead of 5 minutes and a series of commands, it can be 30 seconds and something you can do from your phone. Not perfect, but helpful.
6. Delegation. Some things can't be eliminated or automated, but they can delegated. For a while, the biggest pain in my life was audio editing for my podcast. So I outsourced it. This is a form of "automation" that we often overlook, but it's been great. (I asked @gk1 more about Standard Operating Procedures on this thread, because this is where I see a lot of opportunities for more "automation".)