What policies, technologies, equipment, etc is used to mitigate liquid spills in the cockpit especially during turbulence? While reading this stack exchange question about waterproofing cockpits, I wondered what common industry practices as well as personal practices are in place to mitigate spills and damage.

Type of cups, serving times, cupholder design and placement, length and altitude of flights, weather considerations and sterile cockpits for example.

Additionally, are reportable spill events so uncommon as to not warrant mitigating procedures and design practices?
Keeping the cockpit clean is a major consideration for airlines. The inflight team will scheduled meal times accordingly with reports from ARTCC and other aircraft on a similar routes. They tend to stagger their eating times, so one pilot can be the PIC and the other can eat. Once he/she is done eating they will switch. Here you can find a link explaining Multi Crew Operations. Hope this helps!