This handy article explains which common household items you can use or repurpose as a knitting stitch holder if you don't have one.
A Garden Wedding Shawl Knitting Pattern — Andrea Rangel
Strong and flexible stitch holders. Needles screw onto, and off of, the leather cords. Comes with three cords and two interior-threaded needles.
Leather Cord and Needle Stitch Holder Kit
The truth about left-handed crochet: The differences for left handed crocheters - Dora Does
Using Scrap Yarn Instead of Stitch Holders - PurlsAndPixels
Stitch Holders - a supply and a description.
Using Scrap Yarn Instead of Stitch Holders - PurlsAndPixels
CRAFTWIZ 100% Acrylic Yarn for Crocheting and Knitting - 30x30g Skeins of #4 Worsted Weight Yarn, 1600 Yards of Soft Crochet Yarn, Perfect for Amigurumi Yarn and Other Small Crafts Projects
GADGET – IMPROVISED STITCH HOLDERS; GADGET POUCH CONTENTS
Knitting Stitch Holders
Using Scrap Yarn Instead of Stitch Holders - PurlsAndPixels
Stitch Holders - Yarn Folk
KNITmuch Issue 9 by A Needle Pulling Thread - Issuu