When I learned that I could decide not to do something, it was very freeing and brought order to my life.
It's good to learn that we don't have to do it all. We don't have to say "Yes" to everything. We absolutely have a choice! We can choose what gets done today, what to never do, and what to put off to a later date. This applies to work, business, and home life.
When the decision is made, move forward and don't feel bad about it. You've make a decision, period. For me, it relieved me of undue pressure I was putting on myself.
Get into the practice of making a decision for you, and feel good about it. I found that whatever I decided to not do, was just fine NOT getting done when I first thought it should be done. And often when I put it off until later, it was a better time to do it and it got done quicker.
Before your to-do list seems overwhelming, remember, you can decide what to NOT do!
You can do all you want to do when you bring order to your mind. Releasing the clutter of an overfull to-do list is a giant step toward bringing order to your mind. With a new sense of clarity and order, you will then get everything done that you need to get done, when it needs to be done.