I just use the multicolored embroidery thread, I normally separate it to 3 threads. If you aren't stitching in the ditch or any other quilting then go by the rule of thumb when quilting, they need to be about a fist width apart. I normally do SITD along with quilting, depending on the design and the tie. My daughter loves to tie her quilts too. She normally backs them with fleece which since I've taught her how to use the walking foot she has seen how easy it is to have unpleated fleece on the back. But you can use a straight or curved needle and run the thread down and back up again thru the fabric close together and tie it off. I've also seen where some use the auto thread cut on their machines and do the same thing but you wouldn't have the ends of the thread sticking out. You can also take some of the small designs that alot of machines have built in (like little hearts, etc) and place them ever so often and it'll have the same effect. Good luck.