If something is getting boring or tedious, look for ways to change it. Any kind of long-term goal requires perseverance, and there are going to be days you just don’t want to bother. Look for something new you can add or a way to change your routine.
If you normally write at home, try writing in your car or at a park.
If you usually write in the morning, try writing in the bathroom at work or on your coffee break.
If you’re stuck on a scene, try writing a draft from another character’s POV. You may not keep the scene, but it will help you find a fresh perspective.