1. Go paperless - there is no reason why you need to keep paper. If someone gives you paper, take a picture of it on your phone.
2. Get photos off your phone and into a cloud storage tool. I use a paid Google Drive account which costs around $100/year.
3. Constantly empty out things like bags, purses, etc. to review what's in there, toss what isn't required anymore, and organize the rest. These spaces get cluttered because people throw things into them and never take stuff out to organize.
4. Don't add new items to your closet until you toss old items that you don't wear anymore. If you haven't worn it in the last 30 days, it's time to go.
5. Decluttering is an attitude/way of thinking - I don't have 1 million browser tabs open and I don't have 100 files on my desktop. Why? It's digital clutter which is the same for me as regular clutter.
6. Schedule time to go through spaces like your basement, closet, attic, garage, etc. Otherwise, these places will continue to stack up stuff and it will be tougher to go through in the future.
7. I don't keep my kids art work - if I like it, I snap a picture of it and store it in my cloud storage. Am I a bad parent? I don't care.
8. If someone is sending me junk mail or junk email, I unsubscribe or ask them to stop sending it to me. I don't want it but I take the extra step to tell them not to send it to me rather than just throw it out every time.
9. Drawers - you have to pull everything out of them once in a while and be ruthless in tossing stuff.
10. My desk - there's no clutter around my desk. Seeing too much clutter will distract me from my work.