The key to making a business card that will actually do many of the things that you are hoping it to is to add information to it efficiently once all has been said and is now out of the way. For most people, this extends to reducing how much information they want to place on the surface of the business card in question, but suffice it to say that this is not as effective as they assume. The reason behind this is that adding less information means that your card recipients would have less to go on if they want to hire you for something that matters to them, so instead of adding less why don’t you focus on figuring out ways to convey more information through less business card real estate?
Any Metal Business Kards that you print will have a limited amount of surface area that you can print things on, and using social media icons to convey that your handle is for a specific site lets you use less of this space than might have been the case otherwise. Instead of having to type out Facebook or Instagram, you can just use the small logo which these companies are less worried about people adding to their personal cards.
You just need to go to any site that has the logo on it, copy it from the site and then paste it into your business card design. Alternatively, you can also have your card designer add these logos if you want. This is not all that beneficial, though, and it might just add unnecessary hours to the design process so copy pasting is better.