I started maintaining a 'to-do' list somewhere in the middle of my career life following my superior's habit o doing so.
Even though making a 'to do list' does not mean that we have done the job, it ensures that we do not forget the tasks to be completed. This comes as a very good help and source to fall upon when we have umpteen tasks being thrust on us daily from different directions. It is quite natural that we tend to forget many tasks entrusted on us , especially when they are oral or oral telecommunications.
I used to keep a writing pad and list all the tasks as and when received or entrusted in that pad serially. Then I go on doing those jobs taking the most easy first. Once done, I score of that from the list . Similarly, unless a particular job is of utmost priority, I attend the easier tasks first. That gives me a sense of satisfaction. that I have done'so much' and propels me to complete more tasks.
When I have to leave the office, I carry over the unfinished tasks to the next page under the next day's date. This I try to attend next day first and also attend simple tasks coming on that day also. Thus at any time I will behaving the list of unfinished or unattended tasks. This will help me to delegate or get help from others too.
Now,after retiring from job , I follow same system at home also. Thus I am able to take care of my domestic matters like tax, bills, purchases etc more systematically.
My wife has kept a small white board in the kitchen. Whenever she remembers something to do or to buy, she notes it on the board. While go into market or for errands, I look at that board and incorporate the relevant ones in my list also. So we manage things systematically and it is 'better late than never'.