Max - I use exactly the same way of remembering "complement": If both you and I do it, it must be right.

! I won't even start on the whole "loose/lose" thing - hair-pulling is no fun!

I try to help my students by telling them, "If the os are loose, you might lose one."

It doesn't always work - one replied to me, "If my 'ose is loose, it falls dahn to me ankles."
I suppose he could have said that he'd get wet.