What kind of elixir are you thinking of? Something that you can drink?
If that is the case you can make infused water where you place a glass of drinking water upright into a bowl of water full of crystals. The water inside the glass can take in some of the crystals properties, but because it is in a separate container it is safe to drink.
If in doubt do a full search for the list of poisonous crystals or those that release substances into water, not only will this help with making elixirs but also with cleansing crystals.
Rikki's got a point, not all elixirs/potions are meant for consumption, you might anoint the elixir like a perfume, or bottle and carry it to attract the energy in question. research the uses before consuming it to be safe.