First of all, ask yourself why you need business cards. Who do you give your business cards and in which situations?
Your business card is a very important advertising medium. With well-designed business cards, you can make a great impression.
You can design your business cards yourself, e.g. with Word, and then send the file to the printer of your choice. Another possibility is to create the business cards online. I would advise you to leave the design to a professional. People will be able to tell by looking at your business cards if they were designed professionally or if you cobbled them together.
You should always have a few of your business cards with you - no matter where you go. You can put business cards in your pocket, purse or your deposit them in your car - this way you always have some at hand. You should keep your business cards in a case, so they won't wrinkle or get stained. Never pass dirty or creased business cards. This is unprofessional. Just throw away your useless business cards.
Place your business cards in letters to your customers. If you send an invoice, you can attach a cover letter and also your business card. There are several possibilities for attaching your business cards: Put your business card in a pre-cut mount, use self-adhesive business card pockets or simply attach the card with a paper clip.
When you go to appointments with customers or events, you should always have your business cards handy. Hand off your business card at the registration when you go to an appointment. This way, your conversation partner also does not confuse your name.
If you get business cards from other people, keep them separate and do not put them into the pile of your own business cards - that could lead to confusion, if you have to pick out your own business cards from the stack.
If you are at a trade show where you hand out many business cards, you should make a note at the make about where you met the person and what you discussed. This prevents confusion and at the end of day you can go through the stack of cards again and figure out who to contact first.