XTC's tend to increase the width of the fabric a bit so I prefer to use them in trims or on pieces that I am intentionally increasing. You can alter the pattern to make them not increase the width, but in my opinion, they also don't stand out or have as dramatic of an effect as they do otherwise.
XTC = TC in 3rd st from hk, ch 2, TC in 1st skipped st.
To begin, chain the length that you want the project to be (# should be divisible by 3). at this point I like to do a base row. In the pictures you'll see that I did a base row of HDC's. The first photo picks up after that row. Chain 2,
TC in the 3rd HDC from hook, ch 2,
Chain 2, then holding the first TC out of your way, TC in the second st BACK from the hook.
(See the picture above, the hook is pointing to the correct place to put the stitch)
It's a little difficult to see, but this is how I hold the first stitch out of the way while doing the second stitch.
Here's the effect that you get! Isn't it gorgeous!?
Notice that you don't put 2 stitches into the same hole at any time in this pattern.
Here are some fun instructions for how to do this stitch when working on something like a skirt or sleeve. Again, remember that it will increase in size on the outer edge, so use it with that in mind.
Chain the length that you'd like, and join. Chain 2, HDC around and sl st to join.
Continue XTC's around and watch the texture in this pattern!