Doing Tabata Correctly

I just started doing tabata. I do a 5 min warm up of tabata intervals on my balance balls for my abs then I do my 4 min of workout on a mini trampoline sprinting. then I cool down by doing tabata on my arms. Am I doing this wrong? I want to lose weight and have nice toned abs and arms after I lose the weight. So please tell me if I am doing this wrong and how I should be doing this differently