Move your Flash movies deeper within your site. If your visitor wants to view them, they can simply click on a link. Use Graphics Sparingly. It's irritating to say the least. If you have to display a lot of graphics on one page, make them into thumbnails.
Visitors can click on the image they want to see in order to view the full-sized version.
Forget the Frames. A lot of people like the look of frames. Keep it Simple - and Use Common Sense. The simpler and cleaner your HTML, the more likely it will display exactly as you intended on different browsers. Limit the number of fonts and colors you use.