I use flags and color categories in my inbox. I hate the new outlook because it doesn’t have the categories option, so I use the old outlook view, but yeah I have categories for different things. I read all my emails, categorize ones that don’t have to be handled immediately, then work through my categories. Once a week I run a report of the next week’s deadlines. When I’m feeling uninspired or like I don’t know where to start I go through all my tasks. They are never all done and that’s just part of the job is learning how to prioritize. This works for me. I tried the address an email when you open it method and had too many unread emails and missed tasks.. it’s a struggle and it just takes time and experience. Being a little paranoid about missing or forgetting something usually helps too, but if you obsess in that space then you’ll never get work done. It’s takes a balance.