A helpful trick I've used is the 80/20 rule, which can assist in quickly identifying what tasks are most important.
You assess how valuable a task is and how much time it might save in the long run by considering its potential impact and urgency. Rank tasks based on this - it helps focus your energy on the most profitable action!
Also, I've found that setting clear deadlines, even approximate ones, helps. Assigning a specific deadline makes it easier to gauge the urgency and prioritize accordingly, especially if it's a flexible due date. You can plan and slot other tasks around these cemented milestones.
An additional benefit is visualizing your to-do list; seeing tasks laid out physically - on a whiteboard or poster - allows for a bird's eye view of your workload and lets you assess the order of jobs more easily.
You can then quickly scan and reassess priorities as tasks progress or new ones arise, keeping your focus efficient!