Let's get Started
Creating Banners is relatively easy. It's creating eye-popping banners that is the hard part! If you do not have an extensive background in art or design then I'm going to try and give you the Instant Coarse. You can improve upon these basics by paying a visit to your local library and picking up a few books on illustration, design, color, etc... A Color Wheel is a helpful tool with any art and design project. A color wheel shows you the complimentary colors, primary colors, and all that other color coordination stuff that makes for beautiful, eye-catching designs.
A Little is a Lot
The saying that artists have heard so many times they probably want to vomit every time they hear it. The saying "A little is a lot." which means "DON'T OVER DO IT!" When you get an image that looks good or even great and you think that if you just add one more little thing--don't do it. If you look around at web pages for example you will notice that great, nice looking web pages have lots of negative space. Negative space gives your eyes a place to rest and doesn't overload the reader with tons of text. I have a background in sign painting and have read a great deal of books of typography and layout. You need to keep the viewers eyes moving through the page or banner in this case. Fortunately banners only allow you to only have a certain amount of text which leaves less room for error. More on this later.
Walk away from you Art
A technique that many artists can testify to is to walk away from your artwork for a day or so. When you get to a point where you think your work is OK or Good then walk away for a day and then come back and then make any changes you feel are necessary. If you are working on a piece of artwork for an extended period of time you tend to drop your guard along with your standards. This goes the same for working late at night, if you insist on working into to early morning hours you are definately going to want to let your work sit for a day or at least until the next afternoon. If you get to a point that you think you might be jeopardizing your artwork then create and work from a copy which brings me to the next really IMPORTANT topic.
Work from a Copy NOT the original
I can tell you this until I'm blue in the face and you are still going to make this mistake sometime! How do I know this? I still do it once in awhile. Please, ALWAYS open your artwork and then do a Save As and create a second copy of your original and work with it. What I do is when I work on a piece and I add to something I like and will become permanent then I will save it as a third copy. I save the artwork in stages so I can go back at any stage and work with it. It's not rare for me to have 10-20 copies of artwork for the same project.