There is a computer programming term called GIGO. It means "Garbage In, Garbage Out" and it's a good one to remember when you're designing/printing business cards, postcards, notecards, fliers, all that stuff you use in your marketing.
Why? Because the finished product can be no better than the digital file used to produce it, and printed materials require high resolution images (as opposed to web images which can be very low resolution and still look great).
For example, for a business card the image you start with should be at least as big as the business card at 300 ppi (pixels per inch) and the card should be designed with software (like Photoshop) with color settings for CMYK (not RGB, which is for web use). If you're not digitally-inclined and don't know the difference between CMYK, RGB, pixels and dots-per-inch, do get some help from someone who is experienced in designing for printed pieces. You want your colors to come out right and the image/text to be clear and crisp. You want the design to be consistent with your brand (the design/colors/layout/logos that people associate with you and that you use on your website and other marketing materials).
We do a lot of designing for fine artists, it's not a long process and then they have a file to work with in the future. Above are a couple of examples. When we started working with Deb Copple, she didn't have a brand, so we created one for her (and her website) and now all her stuff is consistent and the minute people see it they know and remember her.
Doing it yourself? Here's a tip: try www.overnightprints.com. I love these people, the results are great (if you start with a great digital file), good prices and fast turnaround. They have templates you can download and use and if you follow the directions, your cards should turn out fine. Tip #2: Wait for the sales they have several times a year when you can get up to 50% off.
But if the process eats up your precious studio time, is technically beyond you, or frustrating for you, please let us help. It's not a big investment and you'll end up looking ever so professional and glorious!
All my best to you and yours,
Web Marketing Mentor
FTC Disclosure: We do not benefit in any way from recommending www.overnightprints.com. We do so because they're a really great resource.