Leeneia:

When hand sewing, put the leading end of the thread into the eye of the needle. There will be less tangling, possibly none.
You can make this mistake-proof by threading the needle before the length you will use is even cut.

Nigel:
An interesting tip, and one I didn't know.
How does it reduce tangling?
If it is because of the way the thread is 'laid up' (individual threads twisted and combined) does this mean that it depends on handedness?
So should a left-handed sewer thread the newly cut end to the needle?

I thought I might get a good clue on this from my left handed daughter who, amongst jobs in a crowded life, has spent time professionally as a hand embroiderer, including for Scandinavian royalty. Her somewhat uninformative answer? "I cut both ends and loop the thread to avoid tying a knot"