For sites who like to swap something smaller makes some buttons with your logo on them. The banner at the top of this page is an example of a 468X60 banner. Offer something of value to people if they do click on it. Try to keep the banner size under 10K for faster loading To build brand awareness about your products and or services use your logo on the banner. Change your banners frequently so people don't get bored and stop clicking on them.
Studies also show a blue border around the banner increases click thru.
Well, there you have it a few tips to guide you in the design process. If you're in need of a high quality banner you can't do any better then my friend Shawn at Artjive. All banners all the time. Learn how to design better banners to increase click thrus. Need some Blank Banners to make banners from, these are beautiful and Free.