Firstly do NOT try to do everything at once! I found that so overwhelming and I never felt like I was really getting anywhere. I'd do a huge clean which in a day or so would start to unravel and make me really disheartened.
I've found that 'little and often' is the magic answer.
In practice this means (and I know it sounds obvious) if I see something on the floor I pick it up as I walk past the first time (rather than walking past 10 times and looking at it and thinking I'll do it later) .. same with school notices or other life admin stuff which i sign/return/note on the calendar immediately as needed.
If something needs to be noted for later it goes straight onto the year wall calendar which I transfer to a weekly wipe off calendar on the fridge each week with columns for each family member including the dog so everyone can see at a glance what's going on.
School mornings: DS1 (11) has his own alarm set and gets up and gets himself completely ready without nagging from me. As long as he's ready by 8.20am he can read or throw a cricket ball or whatever (no screens).
DS2 (10) is completely different and had needed me nagging and giving him time reminders constantly UNTIL we recently printed a routine for him with simple steps. He still needs a few 'where are you up to?' nudges and heaps of praise when he keeps to it but he's now sorting himself out.
DH and I shower before they get up and I pack school lunches while they have breakfast with DH so we're all together in the kitchen for a bit.
I also do a few things which are like little tricks to keep me on track .. I fold over hand and bath towels neatly on towel racks because I find myself more likely to wipe over the sinks/bath daily if the towels look neat. And then I'm more likely to also do a quick bathroom mop to keep up the clean look. The boys help out with this too by wiping sink/mopping bathrooms on weekends.
Same trick with beds (boys do their as part of morning routine) which if made seem to prevent throwing other stuff in the bedrooms randomly .. it sets the tone for the neatness of the whole room.
Having said all of that I've honestly only really gotten this on track about 10 weeks ago as I'm about to go back to study after being a SAHM for 18 mths. As time goes on I'm discovering layers underneath the cleaning/tidying that I'm doing so (for example) cleaning my skirting boards or culling the playroom wasn't a priority while I had piles of washing to put away or kids stuff everywhere, now that the other things are gone I can get to the deeper layers and everything just keeps getting cleaner and more organised as time goes on. And that keeps me motivated!
Sorry that's so long .. hope even one of these tips helps!