To start off, keep in mind that web development, like any other ‘craft’, is a subjective process, and that any one opinion may differ from the next. The idea is not to establish what is right or wrong, but to try to lay down some ground rules and to give you a place to start. Everything has its place, but try to use tools when they enhance what you’re trying to get across, instead of just downloading things and throwing them in because they look neat.
Try to avoid things that have been done a million times before, and are getting a little tired. These might include:
excessive animated .GIF’s
under construction signs
page fade-ins, etc.