8. Make Sure Your Text Is Readable
One of the most unfortunate mistakes in postcard marketing is when a design looks good, but the text fades completely into the background. One of the easiest ways to fix this is to avoid using colored text, and stick with the traditional high contrast black or white. Here's an example below that shows three different shots of the same postcard, one with a color font, one with a black font, and one with a white font.
However, there are times when that won't be enough, and your text might still fade into the background. There are two fantastic options to help fix the problem, and both are extremely easy to do using Photoshop or any other DTP program you feel comfortable with.
The first way is to simply create a rectangle beneath your text, fill it with white, and drop the opacity down to 50%-25%. This will allow part of your image to show through, but give your text the advantage of standing out against it. Here's what that would look like!
The second way is to add a stroke (or outline) of a contrasting color around the outside of your font. Normally, you'll either pick a white font with a black stroke, or a black font with a white stroke. This is done by using Photoshop layer styles, and here's the result you get.