It gets easier once they’re all in primary school!
For the house - figure out the very basic (life will grind to a halt if I don’t do them jobs) and prioritise time for those. It’s likely to be about half an hour worth of jobs. Even if you get stuck into a cleaning project you need to come back to these vital jobs. I know it sounds obvious, but I was constantly focusing on the wrong jobs and not understanding why my house was such a disaster.
Be realistic about how long meal prep takes and budget time for it. Again, it’s stating the obvious, but I had a tendency to try and do too much, then get frazzled at dinner time and just feel like I was always chasing my tail.
Other stuff just has to fit around work and the above things that need to be done daily. So don’t think you can declutter the garage in an afternoon. That kind of job is an ongoing thing, that you can tip away at for months. If you know that then getting 15 minutes worth of progress feels worthwhile. If you’re unrealistic about it, it feels like a constant failure.
Decluttering as pp have noted is really important. But it is an ongoing project rather than a once and for all kind of thing.
Some of my general organisation tips:
Separate bags for all activities - relevant kit gets put back in bag from tumble drier.
I use the alarm function on my phone set to repeat rather than calendar. That way I can snooze (or change time) if I’m not ready for the reminder rather than forgetting it.
I have lists for everything that ever happens. I don’t waste energy thinking (eg what to bring for a weekend away) about things that happen more than once; I just consult the list.
Simple meal plan: mon- chicken, tue- beef, wed - fish etc but chicken could be fajita, casserole, curry, Alfredo, stir fry. Chicken is chopped, bagged and frozen so dinner can be a quick assembly. It doesn’t feel repetitive.
I have repeating grocery orders which I edit, rather than thinking it up from scratch each time.
Take a photo of every letter that comes home from school.
Be purposely forgetful with dc. I am always “confused” whether it’s PE day, or uniform day and from an early age, they kept track themselves. It’s good practice for them!
Don’t worry about getting dc to help out with chores etc while young - it’s hard work and takes years to pay off and slows you down too much. Just get them to pitch in for a quick tidy up, clearing the table after meals, carrying in the shopping together. Those things make a difference and set the tone for later when they’re old enough to be some use.
Always keep water and snacks in the car.