I go with the flow. Usually I can't take the full workday off (meetings that I should be at, etc.), so I try to focus on doing a task that I don't feel friction

I go with the flow. Usually I can't take the full workday off (meetings that I should be at, etc.), so I try to focus on doing a task that I don't feel friction towards. If I feel like I can't get started on something or that it's just not going well, I try to do something else until I find something that I can make progress on. Maybe that means going through my email backlog or making a nice todo list. Maybe it means exploring a low priority side project that sounds fun. Often I find that making progress on a low priority task can reframe my mood and bring me back towards working on the important goals for the day. Some days, though, it's just a lost cause, and it's best to then focus on using the day to recover. You'll feel a lot better the next day if you recover than if you spend 8 hours struggling and failing to be productive.