I have worked in several organisations where I have needed to be dynamic, dropping some tasks I am currently working on to take up something that is more business critical. I create a task list to keep track of anything that needs to be done, some tasks may have several sub-tasks. I add notes for each task, to remind myself of where I was in each task before I leave it to move on to something else (or before I forget). As each task or sub-task gets it gets set as finished removed / a strike through (depends on the tool being used for the list).

The list is only to remind me of what needs to be done, I will often change the order of the list depending on the changing priorities of the business I am working in. I found I need a list as trying to juggle all the tasks in my queue became too difficult and often would require some time to rediscover where I had finished off on a task before I was asked to change to something of higher priority (e.g. migrating a machine to a different version on Linux where a predecessor has not documented the build, compared to an outage on a service in production (sometimes diagnosing an issue in an outage generates tasks to be done on other machines to prevent future issues, the notes will record the relevant commands etc that will need to be run when performing that task).

I will add that I would not live my life based on the the task list, it is merly a tool to aid me as my brain gets focused on other things :D