Dawn asked for pointers on mixing prints. I get asked this one now and then, so I thought I'd toss out some things I consider when mixing prints for projects. (She also asked for photo tips a while back and I'm still working on that post for ya Dawn!)
First, TRY IT! Don't be timid! It is scary at first, and things may not "go" to your eye. You have to retrain how you view prints, and more specifically certain types of prints.
For example, dots are solid. Repeat after me...DOTS ARE SOLIDS. I'm serious. I don't even consider dots (and mostly stripes & checks) a print. If the background or the dot matches a color in your main fabric, it goes. I promise. Here's an example, where I pulled a check in a coordinating color and a dot in another coordinating color to match this rose print fabric.

Once you've got the hang of dots and checks, let's go a step further. There are other "solids" out there if you look hard enough. Two-color prints that combine white or cream (or black to a certain extent) can also act as a coordinating solid. Damask prints for example. Damasks are just a repeating print (like dots or checks). See...

And once you're comfy with the dots and the damasks, here's a cream/pink floral print that has a much larger repeat, but can still coordinate as easily as a dot or damask, even though it is not remotely similar in "feel" to the rose print.

Here's another example of using a "not a solid" print. I love this red Asian print fabric. I've used it a couple of different times for Lu and still have some in stash. If you look really carefully at this print, there is the tiniest bit of medium blue. It's not often and not entirely obvious at first, but it is definitely there. Pair it with that exact blue in another Asian-y print and you have an amazing combo.

You can really see the blue now, whereas before, it was hardly noticeable the strong red print had any blue at all.
Here's one more example. I LOVE this cream rose print. It has a lot of browns and olives and golds in there too, and I found the PERFECT coordinating print by chance one day. It's a dark gold dragonfly print.

Note that it's basically a solid. But has enough of a pattern to break it up and make it interesting, whereas a solid would be a little boring, to be honest.
Let's talk about colors for a second. I start combining usually in one of 2 ways. I either pull from the colors in one print (as all of the examples above) OR I combine prints of the same value. The second one is harder, but once you get the hang of it, it makes the process a whole lot more fun.
My
Candy Dish quilt squares are an example of this "values" type of mixing. All of those prints are the same juicy color palette. Here's a fabric example. These are toned down colors, a soft blue, soft gold, and a medium pink. (Note my pink dot is a little sassy. No reason dots can't be sassy, is there?)

These prints work together because they're all in the same range of value. And I can pull in two dots, because one of them is abstract enough to be a "print" not a dot. Anything that adds more dots is good in my book.
Once in a while, you get a hint from the fabric about what kind of print will work. For this pink paisley print, the paisley's are black & white. What do you know, I have a black & white paisly-esque print in stash! Even though the paisley's are not the same, it works.

Ok one more tip and it's even a nice segue from the tip above. Black & whites are basically "neutral" and go with pretty much anything. Ditto leopard (especially a tonal leopard like I'm going to show you) and zebra. There are certainly places I wouldn't use them, but they add a fabulous punch of whimsy when you're brave enough to take the risk.
This black & white small print floral works equally well as the blue with the red Asian (especially if you hadn't seen the blue first!):

And this tonal leopard works perfectly well with our cream and red floral (as does the deep coral-ish damask).

While you're learning and practicing your print matching, take advantage of quilting fabric lines that already have different prints matched up for you. It's a safe way to play!
For this post, however, I purposefully chose prints that are NOT from the same lines (or even the same manufacturer in all cases.) Because you really can do it yourself. In fact...I prefer to! It's fun!
One more handy tip...paint chips are free at pretty much any paint counter in the world. Go get a bunch and keep them handy in your sewing box. They have the values from lightest to darkest...so if you're having trouble visualizing the same value range, pull out the paint chips that match the fabrics you're considering and you have a visual cheat sheet!
Happy mixing!