The same one you've been using to gain muscle what do you typically do currently?
Typically when starting cutting I will begin with HIIT on rest days from weights and 25mins SSCV 2 x per week on day's I don't train legs. From there its all about adjusting your output (cardio/weights sessions) or intake (food) for continued fat loss.
With HIIT I prefer mind done on a stationary bike or xtrainer, I'll start with 8 sprints done at the time I usually weight train on my gym days so that I've eaten multiple times during the day as I really don't think HIIT should be done fasted.
As far as duration I'll begin with 20 secs sprints followed by 1min40 recovery and repeat - 5mins warm up SSCV and 5mins warm down.
There is no one size fits all but as a very BASIC guideline I would shoot 1-1.3g protein per LB of bodyweight, 20-25% kcals from fats and fill in the gap with carbohydrates. Depending on your lifestyle/job would depend how I would space carbs but when cutting I like a pretty even spread throughout the day with a slight emphasis on workout perimeter but that's more to do with the types of carbs ingested at those times.
K.I.S.S - don't over complicate it here personally at this stage, I would include;
2-3g omega 3's
A quality whey protein/isolate
Dextrose/Maltodextrin if having intra/post workout liquid carbs
Good multi vitamin
5000iu vit d
You can throw everything and the kitchen sink at your body supplement wise but personally I would add one thing at a time and see if you feel/see any benefit from it.
The key to a good cutting period is all in how you manage your intake and energy output in my opinion, its constantly adjusting and evaluating your body and how its reacting each week. Being on top of these adjustments is what leads to consistent progress and of course doing the same things day in day out diet wise and training HARD and HEAVY is key when you are in the gym - NO PHONES, NO MID SET CHATTING get in and work out.
It's hard to give set macro splits and cardio outlines as I would start everyone differently from that perspective. The best thing to do is get a plan down on paper that your schedule fits and you can stick to every day for a period of time, do it for 7-10 days then retake pics/weight and adjust macros/cardio from there.