Keep in mind that every airport is different (my local one is really casual, but I have been to airports where you breathe wrong and they ask you to step aside). These tips are simply advice that I’ve picked up along the way, and are obviously subject to change / specific circumstances. Check this “PackSafe” list for the latest information on what is and is not allowed in carry-on/checked baggage.
Small amounts are fine, as long as they are pump-action. You can bring things like sage, rose, lavender, Florida Water, etc. Treat it the same way as rules for perfumes. These are handy when staying in a hotel, where you cannot burn incense or candles. They will need to be in checked baggage.
Some states and countries have specific rules about soil and minerals, but in general if you only bring a couple of small crystals it will be fine. Obviously decorative varieties will help, such as a heart-shaped rose quartz. Avoid powdered crystals, they will look suspect.
To be safe, stow them in checked baggage. You don’t want to lose a beloved wand to the TSA if they decide it looks dangerous.
Make sure they are clearly labeled (such as the herbs from Lucky Mojo) and only bring small amounts. Herbs that are more obvious, like roots, seed pods or rosemary are easier to get through security. Generic weed-looking bags will be more difficult to transport, and you may want to wait and purchase those types at your destination. Most grocery stores will have the basics.
No matches are allowed in checked baggage! If you really want to bring your own, they are allowed in carry-on luggage, as long as they are regular type and not the “strike anywhere” matches. Most hotels do not allow candles or incense anyway (phone ahead). I know of people who bring birthday candles with them, since they burn quickly and don’t smoke that much.
For those of us who work with sacred water, don’t bring it in your carry-on. Seal it carefully (there are “WineSkin” bags that are great for keeping liquid protected) and place in checked baggage only.
Small animals like cats are allowed, but phone ahead to make sure. Bring them in a small, comfortable carrier; there may be extra fees. Flying is high stress and can be potentially dangerous for small animals, so only bring a cat if absolutely necessary (like moving cross-country). Ask the airline for help determining the dimensions of the under-seat storage area in front of you, to make sure there is enough room. Not every cat carrier is allowed, so check beforehand that yours will fit the parameters. Keep in mind that the cat will be removed from its carrier during security, and needs to be calm enough in a large crowd to be screened in the usual fashion. For more information, this is an excellent article on navigating airports with a cat.
I’ll be adding to this article as I find more information. If you have any experiences to share, please comment below!