The stiffer the wax, the easier it comes off. The best bet is to start with a wax that is stiff. If you buy a rolled beeswax candle,
they can be great for wax. Softer wax is a bit easier to work with at first, but as it warms up it get's messy. So the other thing to try is removing the wax when it's colder. If you need to remove the residue from a card, all you can do is gently rub with a cloth or paper towel on a smooth flat surface.