My first pomodoro of the day is always a 'Plan and Catch up' session.
I begin by checking the results of the previous day's pomodoro and count up the number of full pomodori achieved. This I can use to as a guide of how many I will achieve today. I then do my equivalent of a daily scrum with my team and then can begin to plan my day.
Lets say yesterday I completed 9 pomodori. I allocate nine spaces. Following the meeting I realise that Abdul needs a code review and so I can allocate say 3 pomodori to that task and a quick look at my email shows that I need to speak to Donna about testing a feature. I'll allocate 2. I can now see that I only have 4 pomodori spare. I'll look at uncompleted tasks from yesterday and my active inventory list and pull the the most important ones (or the ones I can finish within those 4). Yesterday was a disruptive day so I hope to achieve more than 9, in which case I will just pull more from the active inventory list as appropriate.