This is going to be a relatively quick section. I’ve covered ordinaries and subordinaries, and now I need to cover the rest of the charges in heraldry. So here goes:
You can put just about anything on a shield that existed in period.
Seriously, anything. And not just things that existed physically, but also things that were imagined, such as dragons, gryphons, mermaids and all sorts of other imaginative creatures can be a charge. I could attempt to cover the numerous types of charges available to you, but no number of pages can adequately cover the vast array of stuff you can put on a shield.
And yet, you’ll see a lot of devices in the SCA that use the same charge. A sword, a unicorn, a thistle, a shamrock, a rose, etc. Why is this? For the same reason the designs tend to be so overly complex: people don’t know any better. They see the limited number of charges and think that these are all they have available to them.
But you’re different. You know that you have an entire library of charges at your command. You also know, from reading previously, that you don’t need to have a sword to show that you’re a fighter, nor a shamrock to show that you’re Irish. Indeed, using your device to display your entire life/persona is terrible heraldic practice. And since you want to avoid terrible heraldic practice, and have something amazing, unique and period, you’re going to avoid the cliches of typical SCA heraldry and find one or maybe two charges that you’re happy with.
One way of choosing a clever, period device is by use of a visual pun, or “cant.” Canting is a period practice of making visual reference to someone’s name (usually their last name) or something else about them. They can be pretty straightforward and boring. For example, if your last name was Talbot, you may have a talbot (type of dog) on your device. Others can be amusing. For example, the Barony of Coeur d’Ennui (translated as “Heart of Boredom”) has a badge with a number of boars’ heads arranged in a circle, aka a Boar Ring (boring). Still others are a stretch. For example, if someone is an herbalist, they may have an arbalest (a type of crossbow that needed a crank to load) on their device (herbalist and arbalest sounding similar).
Whatever your reasons, choosing your charges is one of the more difficult parts of designing a device. Take your time and do your research. I recommend two books on the subject. The first is The Heraldic Imagination by Rodney Dennys. It’s a fantastic exploration of the beasts of heraldry, and has a number of them that are usable, but not used in SCA heraldry. If you can’t find it at your local library or through your herald, you can find it used on Amazon for a very little amount of money. The other is A Pictorial Dictionary of Heraldry, by Master Bruce Draconarius of Mistholme. This is an invaluable resource on heraldic charges in the SCA, available online at Mistholme.com.