making a good design is a lot about something visually appealing to the eye as well as easy to use since the key principle is an interface design.
In contrast with this abstract skill you also have to have a logical grounding to help develop a navigation system into this design,while conforming to all the browsers.
art meets the browser.
If u build a site and work up to a design without a concept on paper or a photoshop image or some image indicating the layout, it will always look half baked in ways.
When making a design think about some basic concepts
art design
colour harmony and vibration
shape and line
positive space and negative space
tech
navigation ease of use
Sometimes it can take a while to develop your own style and it will grow as you develop more artwork.
Have a look at a site called webpagesthatsuck or things of this nature.
Large Images and Huge Titles are always a dead give away.
IT can take a bit of thinking to compress the content you have into the space you have allocated but always looks neater if this process is managed carefully.
Once u have worked out most html commands start on some dynamic content with Perl or php perhaps.
The Black art of interace design should be a book