Hello! (You're Puddle aren't you?)
My tips:
I book time out in my calendar so I don't get meetings booked in that time, i.e. 9am-10am a few days a week to plan.
Towards the end of every week I look at the week ahead and do any prep I need to do for meetings in the following week. So next week I have several meetings and I've already done the preparation so I just have to turn up. I ALWAYS do this, that way you never find you've got hours of prep to do on the same day as a meeting. I already have everything printed out that I need to take. So if the printer doesn't work tomorrow I'm still prepared for my meetings because I did it in advance.
After meetings I always complete my actions (or start them if they're longer) straight away. Then they're done or started and I won't turn up to the next one with actions outstanding. I diarise when they need to be complete by so I'm never the person who hasn't done their actions in the next meeting.
I also try not to get that many actions out of a meeting if possible!
I have a book and I write EVERYTHING down in my book on a daily to do list. I cross tasks off as I go along. If it's not on that list it won't get done. Anything left at the end of the day gets transferred to the next page, i.e. the next day.
I also have a master "task and issue list" which lists my major projects, tasks and issues. Each one has a number, a logged date, a deliverable date, details of the issue, an owner, a status of open or closed and further details of the issue or a link to a separate project plan. It's sorted in date order. This is my master plan and I refer to it weekly to make sure I'm on track. It also means everything is captured and tracked through to resolution. Things never come off here, they are just closed on completion.
Presumably those 20 aren't all direct reports? If they are, sort that out pdq, it's too many. It prob needs 2 managers/team supervisors so you only have 2 directs and delegate to the team via them.
I delegate ruthlessly and well.
If I need a good run at something I close my email and only open it after I've finished my task. OTherwise it's easy to prioritise your time via other peoples email wants.
I use Outlook to remind myself of things, eg if I need to remember a particular thing that isn't on my issue list, like "must have x y% complete by now" then I put a reminder in my calendar.
With emails I do it, delegate it or delete it (having kept a copy if I needed it). MY email inbox only has about 20 emails in it and they're all outstanding items. I get and send 50+ a day so I need to be ruthless.
I book 1:1s with staff in advance so they need to bring items to that rather than coming to me every day. Although they can if they really want to but I don't expect it.
I am trying to train my new team to bring me proposed solutions rather than problems. My old team used to do this , new team need to learn to do it.
HTH. I used not to be an organised person and now I really am.