Frayed tips on shoe laces is about as annoying as things can get. Forcing the little ends of the shoe lace through those tiny holes can sometimes feel hopeless when everything is coming apart and bunching up. I've found a pretty effective and simple fix that takes a few a minutes and costs just a couple dollars.
To fix the shoe laces I needed a lighter, a scissors and some heat shrink tubing. I bought an assortment pack of heat shrink tubing and ended up using the ones that were 3/32" in diameter. You might want to pick up some bigger or smaller tubing depending on how frayed your laces are and what size they are.