Philtre - water-based, delicate ingredients

Infusion - water-based, delicate ingredients

Decoction - for immediate ingestion, concentrated, sturdy ingredients, reduce to remove excess water

Tincture - alcohol-based, keeps for up to a year, time needed for preparation, highly concentrated, dilute

Vinegar - vinegar-based, masks ingredients, highly concentrated

Syropp - ingredients preserved in sugar solution, very sweet

Poultice - chopped plant material, compress, can be infused with potions

Formentation - clothes dipped in potions, compress

Salve - oil- or fat-based, thick and creamy, for external application

Elixir - alcohol-based, very pure

Tisane - hot water-based herbal extract

Macerate - cold water-based plant infusion, requires up to 12 hours

Essential Oils - diluted extracts

Inhalation - vapor from a potion

(http://dept-magical-education.tumblr.com/post/63569406850/types-of-potions)