When finishing your crochet piece, make sure not to cut the tail too short. A short tail will make weaving in very difficult.
Never simply cut your yarn tail off after finishing a piece. No matter how much or how tightly you knot it there's a good chance that it will eventually come undone and start to unravel.
Leave a tail that is about eight to twelve inches long so it will be easy to weave in. Thread your yarn needle. Yarn needles can be found in most common craft and yarn stores.
Insert your needle inside a row of stitches on the back side, or wrong side, of the item. The more detailed your stitch pattern is the more creative you'll have to be with where to put your needle. You can also run the needle through the inside of stitches vertically if necessary.
As a general rule, carry the tail through at least three to six inches of stitches.
Pull the tail through evenly, not so tightly that you distort your stitches.
Now it's time to go back the other direction through the same set of stitches. However, make sure to skip over a loop, indicated by the blue arrow. Skipping over a loop will ensure that the first pass of the yarn remains in place.
Here's another view of me weaving my end back through the same set of stitches.
Here you can see that my tail has been woven in and is now sticking out from the same location as it was when I began.
At this point it's okay to trim the remaining end off with a scissors.
There you have it! My yarn tail has been woven in. The tail may poke out a tiny bit after washing or a lot of use, but it can be carefully trimmed again in that case.
Weaving in ends is a simple but important skill for creating successful and polished crochet projects, yet it's not addressed as often in books and other learn-to-crochet texts as you would think. Do you have any questions about weaving in ends? Feel free to ask them in the comments!