I hold it horizontally by holding one end in my left hand which is also depressing the threader button and the other end in my right hand so the thread goes horizontally across the front of the needles. The trick is to release the threader button and thread at the same time! I wish I lived closer so I could show you. There is a lot of truth in "a picture is worth a thousand words"! Keep practicing - you will get the hang of it!