Sculpey is my friend.
I decided I would need some eye of newt and some Dracula fangs... not just 'vampire' fangs, actual Dracula fangs which are much harder to come by, what with the surprising lack of Draculas around nowadays. At any rate, I used my sculpey to make some fangs and eyes and baked 'em.
While they were baking, I painted some sunflower seed shells... they look like witch's fingernails. Some black acrylic paint and glitter and a potion ingredient was complete.
When they eyes and teeth were done baking and cooled, I painted: The teeth got a coat of white and then a little blood red on the ends and the eyes got a dot of black in the middle.
Once the paint dried, they went in their jars... I found these at Michael's for $0.99 each.
I added some labels to them with vinyl and had four witchy ingredients nicely organized: Fingernail of witch (painted sunflower seed shells), Eye of Newt (sculpey), Dracula's Fangs (sculpey) and Hair of Bat (leftover trim from my burlap runner). Easy-schmeasy.
Now all I need is a potion book and I'm in business.