Agree with the small changes/habits things, where I always go wrong is in imagining I am going to totally revolutionise my entire life in one fell swoop, new routines for cleaning the house, new organisation methods, new work systems, new diet/weight loss methodology, new everything basically, an entire life transformation! I usually get as far as buying the stationary/gadgets and writing up a lovely plan, sometimes I can stick to it for a week or so and then it all goes to pot!
It's a bit of an aphrorism but it takes a long time (some say 100 repetitions) for a change to become a habit, so if you really want something to stick it needs to be manageable enough to do it over and over again. Things that have helped me are:
-Dedicated email/planning time at the start and end of every day to go through the inbox/incoming tasks (nb not actually responding/'actioning', just working out what's there and how I am going to deal with) and prioritising or booking in time for longer tasks. I have a notebook (mine is online but you could buy and use a physical notebook) where I jot down incoming tasks/things people mention to me/things which pop into my head during the day so they aren't lost (but I don't give them immediate headspace as I'm very easily distracted), in my next planning slot I will go through the notebook and book proper time to and sort them out.
-A good shared family calendar that everyone uses, can be electronic or physical but somewhere all in one place where you can see everyone's commitments. We have a house rule that if it isn't on the calendar it doesn't get taken into account, so if you don't put your commitments on you may be 'booked in' for childcare or to go to a family event or whatever and it's then down to you to sort that out.
-Rigorous systematised meal planning, shifts a lot of the effort of thinking about/negotiating/shopping for meals to the weekend rather than in the week when everyone's rushing out/stressed and having hanger fuelled arguments!