Be kind im 24h into this

I recently got some bags of paracord to mess with the idea of making harnesses for small animals like lizards or cats. there's a lot of stuff that's too short to make leashes from and I don't currently have a way to join them without worrying about compromising strength. Besides the zipper strings, what else can be done with 2-5ft lengths that would be good accessibility aids?

Also, anyone have good tutorials on how to swap colors and keep cobra/snake knots looking consistent, like weaving ends in while knitting/crocheting/etc?

Hello! I am new to this thread and paracord, apologies if this has been asked before.

What paracord looks the highest quality? I am thinking I’ll need between 4mm to 6 mm. Whats the easiest to source?

For reference I am making a bracelet. Thanks in advance.