Clover Yarn Threader
This needle threader from Clover is my preferred tool for thicker threads and larger needles.
It will thread multiple strands into a tapestry needle for canvaswork or needlepoint. It can also be useful for threading into a chenille needle for Jacobean crewelwork or for the thicker whitework threads.
For embroidery needles I recommend the Clover Flower Needle Threader or the Clover Double Ended Needle Threader for Fine Embroidery.