When speaking Swedish*, I remember the difference between he (han) and she (hon) using the following concise, snappy 'rule':
"Han sounds like Hans and Hans is a man, whereas hon is almost honey, which is what some people would call a woman."
Of course, by the time I've remembered that rule, the people I'm talking to have drunk so much stinging-nettle schnapps to relieve the boredom of waiting for me to say my piece that they're all comatose in their seats.
* That sounds like a) I can actually speak Swedish properly and b) I speak Swedish regularly.
The truth of the matter is that I can barely string a sentence together and almost never have to. And, even when I do, nobody has the faintest idea what I've said because I've mispronounced all the words.
On principle vs. principal, we were taught "The principal is your pal." Corny, but actually the principal was OK at most schools I went to, even the one who laughed when on the first day of 8th grade I got a schedule meant for a boy.