I have the loop down pretty damn well, so I guess I’ll share how I perform it.
There are a few things I’m always looking to do when I start the loop, and these are probably the most important parts in order to perform it consistently in my opinion.
First, make sure that the sj. after the :s: is performed as early as possible. By doing so you allow yourself to begin the aerial portion of the combo in the same way each time, making it easier to commit the subsequent actions to muscle memory.
Second, the sj. after the Down-Forward Air Dash should be done so that when it hits your opponent, they’re very close to the ground. The closer they are to the ground when you hit them with it, the better. When I do it, my opponents feet are barely off the ground.
If you think they’re a bit too high for your liking, when you land and hit them with cr. -> cr. :h: -> :s:, add a bit of a gap between those hits so that they can fall a bit between the attacks. During the first loop the hitstun decay will not be as great, which allows you to do this. However, during the second loop, you won’t be able to do so since they’ll simply recover and you’ll drop the combo. This is why it’s so important for you to perform the first part of the loop successfully.
So here’s a ghetto diagram to help you envision how the loop is performed:
1.) cr. :l: -> cr. -> cr. :h: -> :s:
2.) sj. - Performed as early as possible!
3.) :f: + :h: -> :df: + :atk::atk:
4.) sj. - Opponent should be very close to the ground when this connects.
5.) cr. -> cr. :h: -> :s: - If the opponent if too high, add small gaps between to compensate.
6.) Repeat steps 2 - 5.
7.) End it how you like.
My personal favorite ender is (in the corner): sj. x2 -> :f: + :h: -> :s: -> :d: + :atk::atk: -> Plasma Beam H -> Air Photon Array -> DHC if desired.
Another fave of mine is (in the corner): sj. x2 -> :f: + :h: -> :s: -> :d: + :atk::atk: -> :h: OTG -> Sphere Flame -> XFC -> Sphere Flame. You can also jump up and air grab them when they recover, and start the loop again for lulz if they’re not dead already.
My advice is to take a couple steps and perform them with the same timing each time, and then slowly add steps as you become more comfortable. It takes a bit of practice but once you get the timing down you should be nailing it 100%. Hope this helped.