Threading your own eyebrows can be quite difficult, even for those people that know what they are doing. It is possible if you are well practised at threading and there are many videos on Youtube about how to do it yourself but first you really know how to thread and shape.
For best results, going to a beauty salon that does eyebrow threading is going to be the best choice.
When you go to a salon performing traditional Indian eyebrow threading, the practitioner will use a piece of cotton thread that is twisted and looped around so that one end is held in the mouth and the other in the hand. The practitioner will then run the thread over the hairs that need to be removed and this will remove them at the follicle. When the eyebrows are being shaped, the practise is the same, the thread being run over the hairs that need to be removed and shaped according to your wishes.