Have you ever made your own wax seals? The ~fancy~ way to do it is to use a marble base. This is usually what you see posted on Instagram. Though it looks more elegant, I prefer to use aluminum foil! It's cheap, you can place a large amount of seals at once, and you don't have to wait as long for them to harden (for the marble ones, they will stick to the marble pretty securely until more time has passed, and then they will sort of lift off of the marble). Basically I hate to wait! So the foil works a lot better for me.
Do you have other ways you recommend? Let me know in the comments!