On ALL of my ukes, I use a length of black 4mm paracord (typically about 44"). One end is tied to the headstock, around the neck, just behind the nut, and the other end is tied (through a loop with a slipknot for adjustment) to the endpin.
When the instrument goes in the case, I lay the 'strap' along side the neck, and allow the excess length to fall in the cavity where the headstock goes. I leave the paracord always tied on. Case closes easily.
One of my pet peeves is having a fat strap that is typically meant for a heavier instrument, that feels bulky, cumbersome, and to weigh more than the uke itself, when EVEN on a baritone, it feels WAY overkill to me. Even Mandolin or Banjo straps are at least 1" wide, which to me is still too fat and bulky for my liking. Other types of straps are always a distraction for me. I prefer the 'strap' to be completely out of the way, both physically and visually, and the paracord is the best solution I've found yet for me.
The paracord never 'slips' when in use, unless I want it to, nor does it cut in to my neck or shoulder as one might think (even if I am only wearing a t-shirt), as ukes do not usually weigh enough for this to happen.
I've tried them all. The paracord works for me, and it nicer looking than a shoelace, which I found that the shoelace actually DOES cut in to my neck as shoelace tends to flatten out from tension, but the 5mm paracord does not. YMMV.
Just my :2cents:.