Sometimes I wrap up a bigger and mentally engaging task with about 15 minutes to spare before a meeting, the end of the work day, etc. For those occasions I've found it helpful to have small odd-jobs close to me (either on my desk literally or as a to-do list). They let me better use my time while I'm at work.
- Updating employee records
- Filing papers
- Writing Thank You notes
- Checking metrics or statistics
- Responding to email