a potion is merely a spell that's liquid. there are healing potions, typically they're tea's. depends on what you wish to use it for, for instance, i've got a cold right now, and i'm drinking a hot honey and lemon with a little chamomile. that's a simple healing tea for soar throats and stuffy noses.
if you have a cough because of mucus or your nose is stuffed up, boiling water and sea salt. pour the boiling water into a bowl with the sea salt, and put a towel over it, put your head under the towel and breath, it stings the first minute, but it will clear it up. that would be considered a brew though.
don't know about healing creams for cuts and burns, i just use Aloe Vera. break off a leave and squeeze the inside onto the cut/burn, and rub it in a little. it cleans it and takes away the pain. i heard it helps prevent it from scaring, but i don't know about that [personally i like scars, they tell stories.]
a potion can be called a tea, brew, bath, oil, stew/soup, or cream, since they're most common. basically, just calling it a potion is fine, just remember it's a liquid spell, and can't always be ingested and you'll be fine.