How to Take HIIT to the Next Level?

I’ve been training HITT for a while now. 2+ times a week for about 30min. Mostly cardio. I’m beginning to get to comfortable with the routine i’ve set.
I’m looking for products/supplements/equipment/routines/programs to take my training to the next level.

How are you currently structuring your hiit sessions?

What does the rest of your training look like?

If you don’t do it already then a couple longer easy sessions will make you better at it.

Other than that you have to up the insensity, reduces the rest, or add more repititions to the HIIT sessions. Ultimately you’ll likely need to change to 3 times per week to keep getting better.