My theme is "keep it simple". No **** on my bike that won't help to get me where I want to go. I don't change perfectly good parts out just for looks. Stage 1, lowered for a better feel, and every other change I made to my scoot has to make sense.

 

A theme is a good thing. I see too many slapdash bikes with lots of accessories on them wich have as only thing in common that the guy who bought them liked them.

Some accessories are nice or cool, but they totally clash with your bike as a whole.
A nice little dirty joke which is a bucket of fun with your pals while drinking beer and watching football, it's not so good on sunday at mass with your girlfriend's parents.
There have to be a common pattern to it all, something that harmonizes it all and that fits in the context.
If you manage it, the result in the whole is much better than even the single coolest accessory you bought was, taken by itself.
If you go for the "I like this, I buy this" you end up with a result much worst than the worst accessory you bought was, taken by itself. And a waste of good parts and money as well.
Look at your bike, try to see which themes are ok and which ones will clash with the current style you got, so that if you try them you either rebuild your bike from scrap, or it will end up half cooked.
I have a '07 FXDC. I like bobbers a lot, but bobber style, with wide front tire, matt black and plain brushed aluminum won't go with my "When I die, I want to be chromated" bike.
It just won't do. So I went for a traditional "Custom" look: more chrome, Kuryakin intake that mimicks the supercharger of traditional tuned muscle cars and so on.
If I want a bobber, I'll buy a bike that has a base stile fit for a bobber theme.

 

My brother has the Live to Ride, Ride to Live things all over his RKC...thing is, he bought it in 2004 new and has racked up a whoppin' little over 3,000 miles since...

I don't know what kinda theme mine has. Was gonna say badassness but someone else already took that theme above and beat me too it. It's getting blacker tho. (gotta change my sig pic one of these years)....

 

Super coolness. In addition, awesomeness.