Plan Before You Design
Before you even consider colors, fonts, and images, you need to figure out what you need to include in your custom ID cards. Why? Because the content will dictate the design. It's easier to play with the design if you only have basic information. But if you need to include additional information such as a phone number, the more complex the creative part gets.
The first step is to put all the information you plan to include in your ID badge on paper. After, move to the next step.
Keep it Simple
The next step is figuring out how to include the collected data. Play around a bit and see how the information looks on a piece of paper (alongside the employee image). Generally speaking, you want the company/organization/school name on the top, the picture on the left, and the information on the right side of the ID badge.
See how the basic design works first. Maybe instead of using a single-sided design, it's better to use a double-sided design. Or maybe, you'll realize it's better to have vertical ID cards. Starting with a simple visualization will provide more answers than you'd think.
Colors, Fonts, Background
The next step is to add some life to the ID card. Warning, don't overdo it.
When it comes to colors, you generally want to use either the same colors that your company/organization uses or colors that go well with them. You don't want to use the polar opposite of your group's colors. Grab a color wheel and note down the ones that will look the best.
For the font, you want to pick a font that reads well. Unusual fonts are fun, but if a person needs to stick their nose to the ID badge to read, what's the point? Additionally, put essential information in all caps.
For the background, you decide. If you want fully custom ID cards, this is where you have the most extensive creative freedom. But that also means the most significant chance for error. If you have coworkers or group members with designing experience, two heads are always better than one.
Adding Extra Features
In cases of creating a company ID badge or employee badge, you often want to add extra functionalities to the ID card, such as QR codes or magnetic strips. Although functional pieces, QR codes, and magnetic strips take ID card room.
Fortunately, since they aren't essential visually, you can use a double-sided design and include additional features on the back of the ID badge. But who knows, you might find a way to make the QR part a creative piece of your custom ID badge.