Interactive Planning Session Question

A few times a month, I facilitate interactive planning sessions between owners and subcontracted engineers and constructors. Normally ill print out a big paper timeline, hadwrite activity descriptions on post it notes and positon them on the timeline before the meeting starts. During the course of the discussion, we'll move the post it notes around to create our baseline plan. After the meeting, I'll input the information into P6 with logic, durations, and resources. At that point our baseline schedeule is created.

To me it seems a little unprofessional to handwrite on post it notes, but that's the standard at the company I'm working for. Is there a better way to do this? Does anyone have any tips on how to make an interactive planning session more efficent?

Thanks in advance!