
Back when I first started selling on Etsy, knitted bags were my thing. Frustrated (actually, appalled) at the cost of commercially available handles, I came up with my own version.

One of the nice things about these is that they can be matched to the colour of the bag. Another nice thing is that they can be removed easily if you want to wash the bag. Which makes them perfect for the printed cloth bags I'll be making soon!
Here's how they're constructed:
You'll need a sharp knife, and a leather hole punch or a hand drill - or something, at least, that can make a decent hole.
Materials:
plastic tubing, about 2mm thick. It's available from hardware stores, and I think it's used for water features and fish tanks. Take care that it's not too thin, or the handles will be floppy, and not too thick, as the plastic can look blue. My handles are 57cm long, so 1.2m should be enough.
2 small cable ties
A length of ribbon or a crocheted chain for each handle.
A bag that needs handles. (These handles are for bags that have a casing around the top edge.)
Cut the tubing into 2 equal lengths (57cm long). Trim the ends, cutting them so that they'll meet each other cleanly, not at an angle.

Make a hole, either with a leather punch or a drill, about 1cm from each end, going through both sides of the tube.
Thread the ribbon or crocheted chain through the tubing. The easiest way to do this is to thread a length of thin wire through, bend the end to make a narrow hook, and pull the ribbon/chain back through.
Feed the tube through the casing of the bag.
Stick a cable tie through the hole in the tubing, through the crochet chain (or past the ribbon), and out the other side. Don't pull it all the way through. Leave the stopper sticking out far enough that it will be able to reach the other hole.

Holding the cut ends of the tube flush with each other, stick the cable tie through the other set of holes. Pull the ribbon/chain tight, knot the ends together, and trim. Try not to cut them so short that they'll be hard to undo. Feed the ends back into the tube.
Push the end of the cable tie through its stopper, and pull it as tight as possible. (Use pliers, not your teeth....) Trim the cable tie.

To remove the handles, just cut the cable tie.