I've been thinking about this a lot lately, the final hurdle of any knitted or crocheted project -- weaving in your ends. No doubt because I have signed myself up this endless task, which is actually a bit different than what I'm going to show you today, because it's crocheted rather than knit. But really, we're all in the same boat.
What do I mean by weaving in your ends? Well every time you finish a project, you'll have at least two "tails" -- one from when you cast on for your project, and one from when you bound off.
If you're lucky, these are the only two ends you'll have to weave in, but chances are there will be more, whether they're from where you've changed colors, joined a new cone of yarn, or picked up stitches to join a new element like a sleeve.
Though it might be tempting to just snip these little fringe-like pieces once you've reached the gratifying point of finishing a project, that's the last thing you want to do -- cutting your ends so close to a knot will make it very easy for these pieces to become unraveled, especially with repeated wear.
So here's what you'll want to do instead. See how, when you have a piece of stockinette fabric, if you turn it over, the back of your work shows all these little staggered bumps?
Using a tapestry needle, you're going to thread your tail through these bumps, securing the yarn in place. (I've used a different color yarn here for visibility, but in your work it will probably be the same color as the bumps.) Start by threading the yarn vertically through two of the bumps.
Then move one bump over to the left, which will be just slightly higher than the one you just came through.
Now you'll come back through that first bump that you started with, on the bottom of your vertical pair.
Now through the very next bump to your left...and then again through the topmost of your vertical pair.
Continue this alternating process, threading through a new bump to the left, and then returning to a shared bump, creating this figure-eight-esque design with your tail yarn.
Although it creates a little bit of extra bulk on the right side of your fabric (a good reason to try to keep this weaving near your seams or hidden areas of the garment whenever possible), this method will keep your tail yarn nice and secure, so that after five or six repetitions, you can feel secure in snipping the rest of that tail and knowing it will stay in place!
I like to do this before I block the piece -- that way any minor felting or shrinking that occurs will help to cement that tail yarn in place even more, and will also help to flatten out that bulkiness just a bit.