How do you manage your productivity while you are at work?

Depends on how motivated i am. If motivation is at 100% i don't really need to manage anything, because i can't stop being productive. If motivation is low i put my phone into "F**k off" mode, close Slack, stop checking emails, take a piece of paper and write down small and achievable tasks. If motivation is at 0% i close my laptop and do something else. No point in forcing it. It's better to just relax and come back strong.

Every day I make a to-do list and try to follow that, in case I assess that a task is not that important I move it for a later time. Prioritizing other tasks that may be prioritized

A combo of tools and habits works best for me.

I'm a big believer in task batching and time blocking - keeps me focused and efficient.