For decluttering, I set a timer for 10 minutes and go in there with a huge garbage bag and a box. The box is for things to donate, the bag is for things to throw away. I'm ruthless for 10 minutes and can easily fill a garbage bag.
For cleaning, efficiency is my secret weapon. I have a spray bottle of my homemade all-purpose cleaner in every bathroom and one in the kitchen. I keep microfiber rags in every spot, too. I have several brooms and dust pans in strategic locations. I'm saving up to have an extra vacuum, one for each floor. This way, if I'm in a room and notice it needs sweeping, I have what I need and can do it in a minute or two. I do a quick wipe of the bathroom mirrors and sink a few times a week and a thorough cleaning about once a week. Since everything is right there, I don't have to plan, I can just do it when I happen to go in there. I use disposable Swiffer dusters because they work, they work fast, and it's one less thing to think about. Plus my kids love to dust if I hand them one of those.
I do not allow food out of the kitchen. Shoes and boots get taken off as soon as they come in. Coat racks and Command hooks at kid-friendly heights keep things off the floor and easy to find.
It's horribly shameful
but I'm not crafty and I'm allergic to scrapbooking. I toss 99% of my kids papers. If they create something that they love, I pin it up on their wall. I stopped feeling guilty long about for not saving their things. My mom saved my things in a big box and I never looked at it.
A huge cause of modern stress is our over accumulation of STUFF. You are giving yourself a gift of peace by reducing your possessions.