We all decide in different ways what we will work and in what order. Here are several methods that in-house lawyers use to make the call. I put these roughly in descending order of frequency, and my tongues gets a bit cheeky.
1. Respond to the loudest voice (the squeaky wheel gets the grease).
2. Do the work first of the highest-ranking client (the general gets the jeep).
3. Tackle what that external powers mandate (Meet statutory or court deadlines or be dead).
4. Pick the work that is most fun or easiest (Lawyers just wanna have fun).
5. Carry on what was unfinished the day before (OCD meets inertia).
6. Do the oldest project first (FIFO).
7. List everything that needs to be done and tackle the most important one first (objectivity, selectivity, and anality).
8. Select the task that gives the company the greatest benefit for the least cost (Economic calculus solves the equation).