Whenever i get bored at work i try to motivate myself, because i notice that as soon as i am less interested, i loose focus and make mistakes.

Therefore i try to keep motivation up. One thing that helps is actually TDD, because you are able to have several small subgoals, which each leave you with a feeling of achievement, when a test you wrote passed, kinda like achievements in games.

When the task itself is so boring that even TDD doesn‘t help, i try to have fun while painfully working through it. Like have a coffee break every now and then or rant with a coworker about the task.

One time a coworker and me had to create a demo in Unity and we hated the task, because it was exactly this brainless and cumbersome clicking in the Unity3D UI which felt awful to us (we are embedded developers and we find comfort in the terminal 😄)
The only thing that got us through the task was ranting at Unity and periodically goofing around in the engine and adding weird behavior to objects.