On my machine the needle has to be all the way UP to the TOP before it will thread with the needle threader. On my older machine I used white out to paint the shaft behind the needle eye so it would be easier to see. Also, make sure you cut the tip off of the thread so it is blunt, "hairy" tips make it harder to thread.
For hand sewing I blunt the tip of the thread, hold the thread between my fore finger and thumb and Pull the thread all the way down so that only a small dot is showing. I set the eye of the needle on the dot with slight pressure, then roll my thumb and finger up catching the thread. This way the thread can't go anywhere except through the eye. Good Luck
Syl