Improving a sites usability doesn’t have to be hard, or expensive. It also doesn’t have to hurt a sites design or appearance. In fact, it can often help. There are a ton of little things that you can do that can make a big difference, and they can often be done in a minute or two. Working on site consistency is your best start.
Consistency
One of the biggest, and easiest things you can do to improve your sites usability is to do things consistently. If your site or intranet has multiple authors a style guide is a must have, especially if there is no main editor. This Texas Electricity site was nice enough to let me use their site as an example.
When digging through their site, I saw a lot of inconsistencies. Templates were different on individual pages, headers were defind differently, colors were different, and font type was mixed up. The site needs some serious help. There are still a couple of items keeping it glued together though, and that is a lot more than some site have to offer.
Saving Their Butt!
There are two main things savings this site. The first thing that is helping them out is their logo. Even though they are using several different templates on their site, they at least continued to use their logo on most of the pages, example page: No Deposit Texas Electricity. Seeing that logo, will at least tell me that I am probably still on the same site. The second thing they did consistently, at least in some parts, was stick to a color theme. Its use is far and few between, but it is still visible enough to indicate I am on the same site.
Overall Appearance
Even though this site isn’t totally consistent, you can see how effective just a little bit of consistency can help a visitor out. This is also a classic example on how doing a usability test can improve a sites appearance. I have heard many say that they sacrifice usability for design. Why? Improving a sites usability should help improve design. By making this site more consistent in some of the major factors like template, colors, and font they could substantially improve usability. It will also substantially make the site appear more professional in design.
Increase consistenty, increase usability, increase professional appearance.

FANTASTIC!