Length of Page
The shorter the length of your page, the better. People don't want to scroll all the way down. Long pages usually mean that you've put too many things on one page. Split things up into separate pages for quicker loading times.

File Sizes
1. The less things to load on one page, the faster the page loads.
2. Don't put too many animated gifs all on one page.
3. Use images in jpg format to reduce file size, use images in gif format for images that have have less colours (eg: icons) need to be clear (because jpg is compressed, making some parts unclear.)
4. Big images take long to load. Use thumbnails for big images.

Use Clear Backgrounds.
Nobody wants to return to a website when they can barely see the words because of the colourful/animated gif background. Also, it looks awful to have a background colour for just the text, because you've decided to make the text legible on a colourful background. Use a solid colour background, save all the fabulous images for other things, and you won't have all these problems.

Use Proper English.
Use proper English. It is PAINFUL to read a site where the webmaster has deliberately wrote in broken English oR hAs WrItTeN lIkE dIs oN dA WhOlE pAgE! Show your personal style in another way - definately NOT in writing.

Organize your page neatly.
Make your page organized neatly: Use tables to make the layout exactly how you want it to look like.

Use a specific colour scheme for your Page.
Make sure the colour of your background matches the colour of your text in the way that the colours go in harmony, and that the background does not make it hard for people to see your text. Make the colours pleasant to look at without straining people's eyes. Don't use colours that have a big contrast to each other.
(example: Light purple background with pink/orange text makes it hard for people to read the text.)
(example: White background with fluorescent green text strains the eye.)

Concentrate on a certain theme.
Try concentrating on only a few things and not too much on the same page - Talking about too many different things only lead you to have a very "general" page without enough going deep enough into any topic, which means that people will lose interest in your page very soon, because there are already too many pages out there like that.

Don't put text that are too big.
Even if you are trying to grab someone's attention, it is NOT wise to put huge text on a page. It only takes up more space on your page, making your page longer, which means that people would probably have to scroll down more to see what they are looking for. If they are interested in what you're talking about, they will read it - no need to make the text huge. The best way is to make the text bold with the <b> tag or strong with the <strong> tag in order to make them stand out. Big text just strains the eye. DON'T WRITE EVERYTHING IN CAPITALS EITHER.

Always add the width and height attributes to images.
That way, it speeds up the loading time of your page, which means that people can start reading your page while waiting for the images to load.

Bars are a waste of space.
They take up more space and loading time on your page and are really unnecessary. Thin lines are okay, but all those fancy colourful anime bars are really useless.
Here are some alternatives:
1. Separate text with images, and images to separate text.
2. Use tables to keep things organized.
3. Use different background colours to separate different sections.
4. Highlight the titles of the different sections by using a different font colour (See how I'm using white for my titles?)

"Under Construction" is a big no no.
EVERYONE surfing on the net knows that websites are always constantly under construction. No need to put it in writing or use one of those "under construction" images.

NEVER take your page down when you are updating your page.
Never take it down temporarily just because you don't have time to update it. It would just drive your visitors away when they see an "Under Construction, come back in x days" page. Do you really think people will come back to a page that may still be under construction and risk being disappointed again? I don't think so. Don't take your page down. When you are updating your page, let people enjoy what you already had on your page in the meantime.

LOOK AT YOUR PAGE after uploading pages.
Many people just upload, and don't look at their pages afterwards, thinking that everything's alright. THEY ARE WRONG. There could be an error in the <BASE> tag (HREF attribute), or a typo in the <IMG> (SRC attribute) or <A> (HREF attribute.) I've seen SOOOO MANY pages where ALL the images on the page are BROKEN, or something is wrong with their links. ALWAYS CHECK YOUR PAGE after uploading them to the server, to make sure that the images are showing properly, and that the URLs are typed in correctly.