There are some very disparate styles converging in this outfit; the western shirt, the punky plaid boots, and the obi-style belt. Because I was trying to make the outfit look cohesive and not create a mishmashed Japanese punk cowboy theme, I was careful in my selections so that the common thread that runs among the different pieces would be fairly obvious. To me it's really the belt that is the crux of making this outfit work. The green/brown combo relates the shirt to the skirt to the boots. The soft yellow color of the cardigan is picked up in thin stripes in the pattern of the boots. Each piece is reinforced, color-wise, with at least one other item in the outfit. Thus, there isn't one particular style that dominates the look and makes the other pieces seem out of place.
I think it's great to mix different styles together and create something completely unique. I love the look of a conservative suit paired with an edgy t-shirt, or a soft ruffled sundress with big chunky combat boots. It's one of the things that draws me to the steampunk aesthetic; I love the blending of Edwardian, Gothic, burlesque, vaudeville, Mad Max-style post-apocalyptic and futuristic elements. But when blending styles it's important to consider what the pieces have in common that unites them, otherwise the outfit will look haphazard and amateurish.
That said, don't be afraid to mix different items that you might assume don't go together stylistically. Chances are that the things in your wardrobe, if they're really you, have more similarities than they do differences. When you scan your closet looking for a top or a skirt or whatever, try to ignore the style and focus only on whatever quality is absolutely essential. For instance, when I started building this outfit I wanted to use the boots, so I decided I needed a shirt that would pick up the green in the boots' pattern. When I came across this one I grabbed it based solely on the color, and was intrigued with the combination. Once I had those two pieces, the rest was easy; I wanted a skirt that was short enough to reveal the entire length of the boots plus a little leg, and it needed to be a solid color. That narrowed my choices down considerably. Once I selected the skirt and was searching for something to put over the shirt, I knew I needed a softer color so as not to overwhelm the outfit with dark tones. The only possible choices were yellow or pink, and since I don't have a pink vest or short-sleeved cardi, the choice was made for me. The fact that I just happened to have the perfect belt with which to tie everything together was just one of those lucky coincidences.
Shirt: La Redoute
Belt: Audra Jean
Skirt: Zara (I think; I bought it years ago)