When designing a website it's necessary to design a website which attracts lots of people and earn money for your business. If a website is poorly designed then visitors will be driven off your website. Here I highlighted some points of the worst web designs that should be to avoid.

• 
  Background music: avoid putting background music on your website. It gives pleasant at first to visitors but surfing each page of your websites with background music may force visitors to leave your site. People with slow net connections have to wait longer to load your website.
• Large/small text size: As I said, there is more to web design than basically graphic design. You should design the composing on your web page to be understandable and reasonably scaly to allow your visitors to research it without worrying their vision. No problem how fantastic the content of your web page or your income copy is, if it's un-readable you won't be advertising anything!
• Popup window: popup windows are used for displaying advertisement. But they are not worth to get attention. Popup windows are closed of the time it appears on visitor's screen.

Let me add more to the listed above .
1. Avoid use of too much flash or animations that has size greater than 2mb
2. Use cool color. This will not affect users eyes
3. let it be u=easier for user navigation

Web Designers who are either fresh to the field, having switched their line of profession recently and others who have just started freelancing for Web Designing, all are committing mistakes while designing websites.
- Lack of Planning
- Failing to use SEO Techniques
- Non-Interactive Designs
- Web Design Contradicts the Main Theme

1)Complex navigation.
2)Failing to use SEO tactics.
3)Non-Interactive Designs.
4) Not good Texture.

The things which you have to avoid to make your websites look better,
Avoid heavy graphics which can bright down the loading speed,
Do not use more and bright Colors   on the web pages
content original and informative.
layout all the elements must be in place.

Yes good informative thread and its fact that avoid the given web design elements which can effect your web design work such as use of too much flash or animations.

According to me its difficult to run your business without any website and It is important though to ensure that your website looks professional and shows your company in a good light. Remember that each visitor is a potential customer and your design should try to entice them in and persuade them to purchase your product. Having a website for your business is a great way to advertise it to a massive potential audience. You might even decide that you want to outsource some or even all of the website design and content to a professional web development company.