Plan what you want to put on the site before you start.
Design your site carefully. Use graphics sparingly and only when necessary as they take time to load and this may put surfers off your site.
Keep your pages themed so that the site is structured.
Don't make pages too long - maximum length is "one side of A4" as a rule of thumb.
Don't put too many images on one page - it slows down loading.
Use image file size attributes in the tags so that the text is laid out properly in the browser before the image is loaded.
Your site should be able to work without graphics being loaded at all - use the alt text attributes in graphical buttons to allow the user to see the button function.
Using the same image eg a logo on lots of pages makes the site look pretty but load quickly as the images are "cached" or stored on the recipient's computer.
Keep image file sizes as small as possible - reduce the number of colours and the image size.
Use the graphical components of html to your advantage eg tables can produce coloured backgrounds and borders, or change the page background and text colours.
Link to other pages on your site - careful planning at the start is important for logical linking.
Make sure your links actually work.
Regularly update the site - date stamp the pages (eg this page was last
updated on)
to show that this is done.