I'm not a super efficient person but I have developed systems to keep the show on the road. I don't cope very well with rushing/being late/not being prepared so I've worked backwards to avoid it.
We have an A4 desk diary and everything is written in there - it has extra space each week into which I write a meal plan and general to dos. I empty/check school bags as soon as we get home and immediately diarise anything from newsletters etc. I fill in and out forms for return straight away (keep envelopes and cash in kitchen cupboard ready). I RSVP to party invites as I read them, write in diary and have a tick list next to each entry for card and present.
I bulk buy cards when in town and party presents from TKMaxx or Amazon when I see something suitable on offer. I get dc to write card and chose from gift cupboard and then i tick off those things on the diary. Every couple of weeks I check my birthday planner for upcoming events and order a gift online, check I've got an appropriate card and set a reminder on my phone to post/deliver.
I have a delivery pass for online grocery shopping and book a delivery a couple of times a week that can be amended up til 11pm the night before. As soon as I find something near empty or a recipe I want to try I amend the basket online.
I have a cleaner once a week which massively helps as the day she comes I whizz round and tidy and empty all bins.
I set up all payments possible to be by direct debit. I save things like dance to my online banking so I can pay fees easily on my phone.
I have all emails synched on my phone and reply to things ASAP.
I plan, a lot. So I'm always reviewing my diary and thinking about what we're going to do when am with whom.
I also take pictures of newsletters, invites, itineraries, term dates, etc and keep them on my ohone or easy reference. I delete once they've happened.
I'm general I rarely stop and often do more than one thing at a time - I would never sit and watch the TV without also meal planning or sorting 'the pile' from the Worktop (a never ending task).