In the time that it took for me to type that and for you to read it, you could have written three tasks in your planner.
The truth is that serious planners spend a lot of time, writing each task in the correct part of the planner, with the correct context code and in a pretty handwriting. We obsess over how the insides of our planners look and function, sometimes so much that the quick aspect of using the planner gets abandoned.
But there is a time for a quick list, and, if you have a planner, there is a place for it.
A quick list of tasks should be created when tasks will be done immediately or soon, right in a row, but there are enough tasks that it is worth writing them down.
For me, the magic number of tasks that must be written down is three. I can't help it. Two tasks in - and I forget what I was doing! (I'm older than I look. This is proof of my age.)
I might write a quick list of things to do before I go to bed.
(Pants, in the example below, mean that my kids must wear long pants with their school uniform tomorrow. I may be getting older, but I do remember to wear pants.) (Um, usually.)
Or maybe I am about to go on some errands, and just jot the order of the errands.
Perhaps I need to proofread the article, email the article, and file the article. A quick list makes sure that, while proofreading, I don't forget to send the article to my boss.
If the day is almost over anyway, the jotted tasks just go in the leftover space on my daily page. Otherwise, they go on my dashboard paper.
The mess of the rest of the page, combined with the big circles notating tasks, makes the list jump off of the page visually when written on an otherwise complete day.
Planners are an excellent tool. Don't forget to use them for their primary purpose - to get things done that need doing.