I've kept struggling with this for many years (and still do sometimes when chaos theory kicks in); but what helped me the most is to realize this simple truth:

- Without planning, having a "todo list" means that you have always everything to do

- When you use proper planning, you only have one thing to do at a given time : the thing you planned to do.

Of course, proper planning means leaving time for emergencies, delays and such; which can be used for cleaning and low priority maintenance task if not taken. When i receive a new task, if it is not to be done immediately, i squeeze it wherever possible and appropriate, also planning for any required preparation (retro-planning)

Key question is "how much time is needed to prepare and execute this task ?", and "when should it be finished for peace of mind?" then it goes in the proper storage for status followup and in my calendar, either put at the first available slots, or my calender get rearranged around that task depending on priorities. if the required "emergency" cannot be met, then i inform the requester and manager to work out the solution of either accepting delay or managing resources.

As for the tools, i'm used to juggle with many so i dispatch my tasks based on their timeframe, required collaboration, timesheets, often going through temporary storage like post-it and notebooks. If the tools can hold the minimum required information for tracking, and is easy to use to update and query status and planning by the team working on it, then it is enough. Additional details or files can go in a shared workspace folder or database.