For me, it depends on the length of the workout. If I'm doing a 30 minute high intensity set, I always do 15 minutes warm-down cardio (jog, swim, row etc). The 15 minutes after routine is an easy way to fit in the cardio without changing your normal workout routine.

If I'm spending 45 minutes to 1 hour in my workouts, I usually split my training into AM cardio, PM weights + 15 minutes cardio.

For cutting or for aerobic stamina, I switch to 1 hour cardio PM (or jog from work to home). It burns that fat off fast (which shouldn't be a problem if you're on the juice) and keeps the heart healthy.