Whether you are looking to just spice up your workout routine or you are looking to burn more calories and challenge your body, then pyramid training with cardio variations could be an option.
Pyramid training can assist with the development of increasing your endurance, and a good way to gauge your progression.
You can start off with no weight, and then slowly starting adding weight here and there to workout. Take breaks when you need and in between exercises.
If advanced, work yourself back up (starting at 10 and ending at 100 reps) after taking a 3-5 minute rest period.
(Note: The exercises may have different names to them.)
90 Walking lunges
80 Seated russian twists
70 Squat to curtsy lunge
60 Mountain climbers
50 Plank jacks
40 Split lunge jumps
30 Jump squats
20 Lunge kicks