I've made 3 of them last week. I didn't like the idea of them not having something in them, so I used felt. I've been using felt for signature wallhangings, easier to write on. I cut the felt to match the runner, including the pointed ends. I also used adhesive spray to hold it in place. I SITD down the sides of the runner and edge stitch the ends. Then I stitched around some motifs in the fabric. Takes about 5-10 minutes to do the additional work, so it's a 15-20 minute table runner, not a 10. Worth it to me.

I use the "partial" method described by several others and fusible Pellon fleece. I sew the 12" and 18" together, lay it out and mark where it's turned to make the pointy end. The fusible is then cut to that size ( and comes to a point on each end) and is fused on. It was too "loosy goosy" for me without the batting.

Yes, and it work beautifully. Just a little meandering quilting or other simple quilting and Ta-Da ready to go.

I have used fleece before for the batting as well as regular batting but I like to quilt mine so batting is necessary. I make them as gifts mostly and feel they need some quilting to make them a quilty gift for friends who know I quilt. Hadn't thought about fusible batting but I use up pieces of batting inside them.

I've done several the same way as this post from Iclang, and they always lay nice and flat on the table.

Here's mine
 

I finished table runner this afternoon. Hoping the photos show up Ok. This is new to me!
Thanks for all the suggestions for putting batting in. I ended up putting Warm and natural in it.
Laurel

Except for being upside down. I think I did pretty good posting the photos.
laurel

Yes you did, congrats! Love your version with those fabrics.

Yours is very nice. I've put batting in mine. Just sew the two pieces together and cut the batting to size and slide it in. I end the batting at the place where the ends fold in since I don't feel those need batting. I've also used flannel. It makes it a bit more substantial, especially when given as a gift.

I found I like to put batting in the body of the runner but not those points you fold over. They were too bulky for me.