If a plug-in is not absolutely needed on your page, don't use it. Not everyone has the same plug-ins loaded and many will not want to take the time to download it just to see your page. Sometimes people move or kill their pages. Make sure all your image and sound files are working correctly Check your spelling. This is especially important if your page is commercial.
Poor spelling looks very unprofessional and can be a subtle turnoff to potential customers.
When a browser has to stop loading a page to look elsewhere for a linked image or sound file it slows down because not only does the browser have to go to the outside source to find the file, it has to return to your server to pick up where it left off. Code - One of the easiest ways to learn HTML, JavaScript, etc. is to look at the source code for another page and see how things work. It does require a basic knowledge of the different types of coding to do so, though. There are a lot of neat tricks that can be done with coding and most code writers will be more than happy to share their source code with you if you just ask. If you see something you would like to incorporate into your own pages, take the time to e-mail the author and ask his or her permission.