For my first few months of slinging many moons ago I used nothing but an Appu-sling which is an open pouch Three Strand Sheep Shank or TS3 sling.  The first good sling I made was a Rockman.  These days  I mostly use a modified pj, a closed pouch TS3, and a Rockman.  I have used many other types of sling but these seem to be the three that I'm most comfortable with.

Ha!
Yeah, J, I hear you.
In your experiments, did you make any braided/woven Y-slings?  If so, how?  I've been trying to figure that out.  Maybe start a Rockman or huaraca and never rejoin the release cords?
I'll probably just give up and end up using athletic tape for the half-pouch and call it done.

well I have favourite slings for different applications.

the ones I currently like making most - I can't tell you about lol
No really i can't
But they are pretty cool.

You can't beat a cap paul for throwing anything - and you get to batter the living snot out of some brass effect rivets with a hammer till they are flat.

So that's always fun.

As the technology and machines i own changes - so does the way i make slings.

Should the internet explode and life on earth be thrown back to the stone age.
I might start braiding slings (well right after I raid the local amazon warehouse and liberate all their paracord - among other things)
Assuming there are books on braiding in the library - 'cos if the interweb dies, I'm starting the scavenginging at a library

To actually answer the question.
hmm.
Well i started with leather shoelaces and - no clue what the pouch was made of, this was over 45 years ago.
I used a 6 hole leather pouch for a while, then butterfly pouches and now I mainly make cap pauls for my own use.

With 3d printed designs for selling to the local dog fraternity for water proof tennis ball slings.

But as i already make the best all round sling design on the planet - It will take something truly remarkable for me to change again

I'm pretty sure that I have alwaysb attached cords to pouches with loops that grip the sides of the pouch and don't stress the hole.
As someone who's been fishing since they were knee high to a gudgeon.
It's a way of attaching things I'd used  a lot.  So came naturally.

almost every time i get new materiel to work with from leather pouches and paracord to fully braided belarics

you using the maize skins/wrappers or the 'silk' ?

@Sir Missalot: Really? Did he smoke the leaves by themselves or use the leaves as wrapping paper for something else?

To answer this question...let me see. Started with shoe string and cut up leather gloves. They were horrid. Then went with 3 strand braided apaches. Then peruvian slings and the paracord apaches. Finally the last big mental change was with a balearic sling which was quite nice. So really not all that much over the years.

I do have a design in mind that I think will be one I attach my name to. I think it could be quite interesting. More on that later though.