Shoes sometimes come with laces that are too long. That's especially troubling on hiking boots - the last thing we need is another tripping hazard! Here's how I shortened mine with simple supplies and tools I had at hand: heatshrink tubing, scissors, and a heat gun.
Step 1: Size Your New Tips
Feed one end of your lace into the tubing to cover the old tip. Pinch and trim. Precise length is not crucial, but you'll be happier if you cut straight across. Cut a second piece to match and feed it onto the opposite end.
Step 2: Determine New Length
Put on your shoe and tie it until the bow is the size you want. Scoot up the heatshrink on one end until it's at the right place. For mine, that was about one inch above the heel.
Step 3: Line Up Ends and Trim
Bring both ends to the center of your shoe and line up the tips. One side will no doubt be longer than the other. It's important to keep the tips together and centered on the toe, so don't give in to the temptation to pull up the slack on the long side. Move the tubing on the second end to line up with the first. Cut off the laces at the end of the new tips, leaving a bit of fringe sticking out the end.
Step 4: Shrink 'em!
Using your heat gun on low setting, start heating up one tip. Take your time; you don't want to scorch or melt the lace above the tip. You do, however, want to melt the very tip, so use the gun on the protruding fringe of the lace. Do the other end.
Step 5: Good to Go!
Walk in confidence that your laces won't drag on the ground or trip you up.