Replacing/repairing transparent/invisible straps?

About repairing/replacing broken or yellowed straps on clothes/accessories and shoes. As they tend to deteriorate with time, it could be handy to learn how to best fix 'em - especially on shoes/sandals.
Anyone has any good tutorials or resources?

Edited July 25, 2022 by Yumeiro

I'm not sure if you've already found an answer as this post is older. but...

i dont know of any tutorials, but i would imagine you could find, lightweight clear elastic at a craft/sewing store like this: https://www.joann.com/dritz-clear-elastic--5-yards/1923689.html?gclid=Cj0KCQiA4OybBhCzARIsAIcfn9m5E8ksRjaoPYXzu7iLFwhoqC1x3JELVmIEZ8r7xrT5slD58Qnr2loaAn-GEALw_wcB  similar to the elastic they use for clear straps etc. 

it should be able to be sewn in, or maybe glued; but be careful to test that any glue you want to use will not harm the fabric/plastic clothing you are trying to repair. (possibly liquid stitch? but test first)