I am new to cloning myself, but the most important thing seems to be humidity. They need LOTS. I had one of these laying around
https://www.amazon.com/gp/aw/d/B07H8P25LS?psc=1&ref=ppx_pop_mob_b_asin_image
And found it to work great as a humidity dome. Keeping the clones in there and spritzing them and the lid with water once or twice a day until they set roots seemed to make more of a difference that what I choose to root in.
As for how I do the actual rooting, I dip the cutting in a rooting gel (doesnt matter which, they all have the same active ingredient, but I use cloneX) ... Then straight into some rock wool (your insulation cubes) and into the dome. I dont care for rockwool, I have better luck with jiffy pucks, but it doesnt really matter. Patience is the other big thing. Takes longer than ya expect.
My first runs of clones, I tried multiple cloning techniques and settled on what works for me. You will do the same