I used to use Outlook (online and desktop) to organize using the GTD (Getting Things Done) method specific to Outlook.
However, I found that while that was good for compiling items, it didn’t help me really focus and ensure that I was getting the most important items done each day.
I ended up buying the “EVO Planner” through a Kickstarter campaign — there are 4 versions, each suited to a different ‘brain type’ (https://projectevo.org/). In the end, I was less interested in my brain type and more interested in using the various formats and picking the one that worked best for me (“Explorer” format worked best for me, even though their quiz said I was an “Oracle”).
With the paper planner serving as my “focused list” and Outlook as my master list, I have found it much easier to focus and make sure I was consistently working on priority items despite distractions.
I think paper and online/digital is a stronger combination that one or the other — too hard to maintain and re-prioritize lists on paper, and online/digital just has way too much information to be useful on a daily basis.