David Allen's suggestions are good as long as you don't make yourself crazy. Take the tips that serve you and dump the rest. Tickler file? Waste of time for me. I did tape "DO DEFER DELEGATE DISCARD" on my computer monitor at work after reading the book to help me get through e-mail more efficiently. With 663 messages in my work e-mail in-box alone, I clearly still have a ways to go on that one.
You may note that I have a whole unfilled column on my list with the title "fun stuff." Gotta work on that. But I find that as I progress through my tasks, some of it can be fun. Like discovering that someone does, in fact, make bifocal reader sunglasses. I think these will be awesome for my driving vacation with the family and in my soon-to-be new role as an auto commuter. It's weird in the car that I can't read the dashboard dials or radio without putting my reading glasses on, so these bifocal reader sunglasses will hopefully solve that. Plus, I'll be able to sit in the sun and read comfortably without squinting. I wish I'd invented them!
I also am replacing my lost Fitbit One charger. I'm sure my old one will turn up as soon as I have the new one out of the package, in which case, I'll keep the duplicate at work. Then I'll be sure to never miss a step. Har har.
Then there's the mindless and time-consuming tasks. I don't really mind mowing the lawn usually. Scanning pics for my niece is fun too. Finding time for both is the part that feels stressful. Maybe I can offer a cash reward to my kids for helping with those projects. Everybody wins!
The rest of the stuff... well, it's just stuff I need to do. It'll probably all get done. Or nearly all. Some of it absolutely HAS to get done. Other stuff... We'll see, anyway. Likely nothing too bad will happen if I miss a thing or two.