Pick letters one at a time. Six wrong guesses and the word stays hidden.
Hangman has been a paper-and-pencil staple for over a century because the game mechanic happens to teach English letter frequency. Players quickly learn to guess vowels and common consonants (E, T, A, O, I, N, S, R) first, because those letters carry the most information at low cost.
For vocabulary learning, hangman has an underrated property: when you fail to guess a word, the answer is revealed alongside the letters you got right and wrong. You see exactly which letters were unexpected — and that surprise is what makes the spelling stick. Word games with too much hand-holding don't produce this kind of durable memory; the small sting of being wrong is the feature, not a bug.
Six lives is a tradition, not a constant. Some prefer harder versions with fewer. The number matters less than playing daily — your letter-frequency intuition keeps sharpening as long as you keep playing.