Here are 10 tips to make an interesting business cards:
Keep the basic design principles: e.g: set your image/photo in 300 dpi, work in CMYK format, ensure your minimum text / font size to maintain legibility.
Explore and get creative within the constrained
Avoid common mistakes / pitfalls, e.g: always incorporate a bleed on your design, don't use a straightforward border around the entire card as this will show up any misalignment in the trim if the card isn't perfectly cut.
Use special finishes, e.g: use special finishes such as spot UV, metallic inks, hot stamping/foil, embossing/debossing.
Cut into your card, e.g: you can apply special cut / die-cut into your card
Try out unusual materials
Make it useful, think that your card can function as something else maybe bookmarks
Make your own
Use recycle card / stocks, an interesting recycle stocks can make your card looks standout
Double check your artwork, last but not least always check your design / spelling / format before you send them into printer to avoid any disappointment later on.