If you have it very short, then actually using the phone would be tricky, no? Especially if you wanted to take a photo - you'd always be holding it very close, or taking it off from around your neck.
I’ve worn lanyards for the phone before around my neck without a problem. I usually kept them where my phone was down to my stomach, just above the waist. It works pretty well actually.
I am supposed to get my Apple strap soon, hope it will not be too long. I usually just had low quality ones from gadget markets in Thailand, so I’m hoping I can finally have something with really good quality.