I've found that mixing up not only what I do, but also when and for how long really has helped. Some days I do a single long work out, and other days I do multiple 10-30 min workouts peppered throughout the day. I currently work from home, so I have the ability to do this. For whatever reason, the added flexibility of different length workouts keeps it interesting. I also do a variety of different types of workouts and pick which one depending on how I'm feeling. You might try circuit training. Since you are rotating exercises and can challenge yourself in different ways (timer, completing x amount of circuits, etc) it adds a bit of variety each time you do it that can help shake things up. When we first locked down in March, I googled no equipment crossfit wods because I live in a small apartment and wanted some cardio without upsetting my neighbors. There are thousands of different routines that you can find online. I'm sure there are even more for strength training.