A seamstress with 60 years of experience told me this secret!

Homemade items
Threads (for threading)
Needles
1 Toothbrush (no longer used)
Empty blister pack or empty tablet
Swab
Cable
Thin paper or cloth (piece)
Step-by-step procedure
With the toothbrush, simply cross the thread from one side to the other of the brush and take the needle from the side of the eye where it is threaded, press a little and the thread is inserted through that channel.With an empty tablet or blister pack of tablets, simply cut a thin strip, make a small cut on one of its sides and leave a tip. Next, the test is done by simply placing the thread in that cut and passing the needle from the same hole or the eye, passing the thread in this way safely.
With a swab, proceed by cutting the sides with the cotton of the swab and thus we will have a kind of plastic tube. A thin wire or a bristle from a broom is threaded through it, creating a little hook. This kind of hook is used to easily pass through the eye of the needle and insert the thread to be threaded.
This is probably the most common and well-known method. It consists of slightly moistening the tip of the thread with saliva or water. This helps the fibers of the thread to stick together, making threading easier. Although simple, this trick is very effective, especially when the thread frays easily.