I'm a big fan of the "55" workout. In it's traditional form it is usually done as push-ups and air squats. With that in mind, the idea is this:
you do 1 push up and 10 squats, then 2 push ups and 9 squats, 3 push ups 8 squats, and so on. You repeat the pattern until your last set is 10 push ups and 1 squat.
At that point you've done 55 reps of each (10+9+8+7+6+5+4+3+2+1=55).
It's a neat idea. What I really like about it though is that you can use that model of Any 2 workouts.
For example, you could do squats and pushups, or pushups and crunches.
You could also do walk 10, 'sprint' 1, walk 9, 'sprint' 2.
You could cross up your running and work out and do run 10, do 1 burpee, run 9, do 2 burpees, etc.
This morning I did dubs and C&J
1 double under, 10 clean and jerks, 2 double unders, 9 clean and jerks.
By the end, it was Brutal. In trying to do it "for time" and racing through as fast I could, the exhaustion level gets so high you start missing your double unders (catching a foot). Each double under missed, for whatever reason (especially at that point in the workout), feels like 10 successful ones as effort goes -- And 55 double unders and 55 clean and jerks as fast as you can go...heck of a workout!
Play with it and see what you can come up with. Using the "55" model and randomly picking Any 2 things will give you quite the workout, with no guides and no real planning!