We actually use the Tabata program quite a bit at the CrossFit gym that I go to. Here is the last Tabata work out we did.
We started off with a 1 mile run
They broke it into 4 minute round, each minute dedicated to a certain exercise
It was 1 minute Push Ups 20 second high intensity, 10 second rest
Next minute was 1 Minute Box Jumps 20 seconds high intensity, 10 second rest
Next minute Pull ups 20 seconds high intensity, 10 second rest
Next Minute Burpees 20 seconds high intensity, 10 second rest
Total 4 minutes
Run 800 Meters
Then repeat Tabata, finish off again 1 mile run.
In a nutshell in those 20 seconds do as many reps with as much intensity as possible.
We've mixed up the Tabata before with Kettlebell Swings, Tire Flips, Deadlifts, Squats etc. I hope this helps.