Let's talk techniques:

I default to a modified "Getting Things Done." Anything that comes across my desk, I either delegate to an admin, do it (if it's < 2 minutes to complete), or it goes into a Trello board. The exception is anything non-urgent, usually email, winds up in a label in Gmail that I circle back to once a week (blocked off hour on my calendar).

I'm not recommending this, but I work on whatever feels right at the moment. If I'm super excited about a project, I work on that. If something is overdue, I feel guilty and work on that. It feels good in the moment, but this “method”, if you can call it that, leads to a lot of guilt and missed deadlines some times. It's worked out relatively ok for me, but I feel I'm holding myself back by not doing what I should do and instead doing what I want to.

My decision-making process is simple, First question do I have all the information? If so, then my decision would be broken if I make a decision, is there a follow-up, analysis, and downstream effects which I have to look through?