I've been searching through the archives, and I cannot seem to find any guidelines that address my exact question, so I'm hoping all you lovely ladies can set me on the right course.

I love interesting, statement making, bold pieces. So I have a lot of them. Predictably, they're pretty tough to style. And then I have a (much smaller) selection of the most uninspired, frumpy, matronly pieces you've ever seen, from when I decided that I really needed to get some plain basics to mix with. The issue is that these pieces actually can't be worn with most of the statement pieces anyway, because they're SO plain that I look like I'm wearing halves of two different people. I know not every piece can be a statement, but right now the disparity between the two types of garment is really jarring.

There are a few pieces I'm eyeing online but I don't want to buy until I have a better way to gauge if they are actually going to fix the problem. So, any tips for how to find that sweet spot where items are interesting without being boring? Some kind of easy rule to remember? I feel like there's an obvious answer here, but I can't figure it out.