You apply HIIT principles to almost any exercise selection as long as you apply the basic parameters with 20-30 secs on and 10-30 secs off - or there abouts depending on what studies/programme you decide to read at the time and your base level of fitness.
eg.
-Sprinting 100 metres, jog 50 metres, sprint 100 metres, jog 50 metres etc.
-Rowing all out for 30 secs, rowing slow for 30 secs, etc
-Pushups for 20 secs, rest for 10 secs, pushups for 20 secs, rest for 10 secs, etc
-Fast cycle for 30 secs, slow cycle for 20 secs, etc
-Chin-ups for 20 secs, rest for 10 secs, chin-ups for 20 secs, rest for 10 secs, etc
-10 punch combo, rest for 10 secs, 10 punch combo, rest for 10 secs.
-Circuit training is really just another application for HIIT with the breaks between stations your rest period.
-Skipping with a rope is also really good. If you follow a boxing protocol and vary the intensity, again, this is pretty much following a HIIT style.
You should be starting at a time of approx 2-5 mins (depending on your current level of fitness) and working your way up to 15-20 mins. If you can go for longer than 15-20 mins then you're most likely not puting in enough effort.
EDIT: I should have added the ratio of work-rest really depends on your level of fitness. You start off with a higher level of rest than work until you can adapt. Once you get used to how taxing it is you will need to change your ratios to suit your level of fitness.