I think because I have a "forever" hexie project (and I've made and sewn together thousands of hexies), people ask me things like the following:Well, here are the answers to those questions. First, I like Superior's 60-weight polyester thread. I have tried quilting thread, silk thread, and others. I like The Bottom Line thread because it is VERY thin, but it is easier to handle than silk thread. I most often use gray but have purchased it in other colors. In the samples you will see below, I have used a gray thread. If you sew the hexies together correctly, you won't see the thread anyway. Here is what the spool looks like.
I know that, when basting, some people do not stitch through the hexie papers. As you can see, I do.
I have tried the other method (stitching just through the fabric), but I find it doesn't hold the fabric tight enough to the hexie papers for me to get really crisp points. I get much less shifting of the fabrics when I'm stitching the hexies together if I stitch through the paper. I put a knot in my quilting thread to start the basting. I always put my basting knot on the "good" side of my hexies for ease in removing the basting threads later on. (See white hexie on the right-hand side in the above picture.)
I work my way around each hexie making fairly large stitches (so they are easy to take out). I DO NOT knot the thread to end off. I stitch an "X" in the last corner and leave a short tail of thread on the "good" side of the hexie. I always stitch through the "corners" to hold the fabric down. You can see all that in the above picture.
I used to hold the hexies--right sides together--and whip stitch them. I have found that holding the hexies side by side (flat) and stitching them together works much better. It is hard to get used to, but the thread shows much less on the "good" side. You can see how my needle is inserted in the picture below. That is how the hexies are situated when I stitch them together. Be sure to slide the tip of the needle off the hexie paper--DO NOT stitch into the paper at this point. If you do that, it will keep the stitches from showing on the front of the work.
Here is what the front of these same hexies looks like. The "connecting" stitches are virtually invisible from the front. The black and gray thread that you see are my basting threads.