There is so much that can be said about proper web design, and many books have been written on the matter just to give you and idea. If you know what web design mistakes to avoid, then your efforts will be that much more satisfying.
When somebody visits your website, it shouldn’t take them more than a few seconds to figure out what your site is about. You should aim at making your site attention grabbing but at the same time clear when it comes to passing the message as to what it is about. You just cannot induce any discomfort on your visitors, with your site, and have any reasonable expectation for them to continue using it. Another very important concern is for your text – no long paragraphs of text that just run on down the page. Huge pieces of content do not make the grade; you have to break it up so it looks easy to read. You need to use a lot of white space wherever you’re putting your content so that your visitors are able to scan your page and know what the content is about. Plain old easy to read font is what your copy needs to be written with on your site. This is about design and usability concepts that are critical to the success of your site.
Another important consideration has to do with your URLs, and they need to be manageable. There was a time when this was something you had to live with. Yet, some people who own sites still have them, and that may or may not work against them.
Google has devalued the power of domains with keywords, but these domains are still a bit more powerful than having no keywords. You really do want your visitors to be able to remember your URL, though. There is also something that is unprofessional about those kinds of URLs, too. There are blog plugins, if you have a blog, that are designed to help out with URLs.
If you really need help, consider hiring a web design company. A good website design company will help you avoid all these mistakes. Even a low cost website design company can be good too, so make a search and see what you can get.
A high bounce rate can be caused by many things, and a site that has too much crammed into it could be the culprit. We do feel most market audiences will not really approve of this appearance and will leave very quickly. In the end, it is your call as to what constitutes that “cluttered” look and what is too much. The need for seals and other images may be valid for your site, so figure out how to arrange them neatly. But be careful and do test because you can increase conversions with some professional images, awards, etc. The more clean and clear your site looks, the better impression it’ll end up making on the end user.
If you are just starting out, then always continue learning as much as possible about design mistakes and usability concerns.