Loose means ill-fitting and likely to fall off.
Lose means to fail to keep, no longer to have, and, of course, not to win.
‘Loose’ at least looks like its pronunciation. But it fails to rhyme with ‘choose’, which, paradoxically, is a better match with ‘lose’. Of course, ‘lose’ doesn’t rhyme with ‘chose’, either. No wonder people from other lands have such difficulty learning English. And, I don’t know about you, but the more I look at ‘lose’, the less it appears to be spelt correctly.
Anyway, here are a couple of sentences that might help you remember which to use:
‘If you choose to wear your knickers loose, you may lose more than just your knickers.
‘Lose your belt, and your pants will become loose.’
Pic: A patch of Rose Bay Willow Herb, which looks great in the wild, but is a devil in your garden.