When building a website for a business, there are fundamental design principles that must be considered to ensure that the website is user-friendly, visually appealing, and ultimately effective in achieving business goals. Here are some do's and don'ts to keep in mind:

Do's

1. Do prioritize user experience (UX). The user experience is critical to the success of a website. Ensure that the design is intuitive, easy to navigate, and visually appealing.
2. Do optimize for mobile. With the majority of internet traffic coming from mobile devices, it is essential to design for mobile first. Make sure that the website is responsive and loads quickly on mobile devices.
3. Do use clear and concise language. Ensure that the content is easy to read and understand. Use headlines, subheadings, and bullet points to break up text and make it scannable.
4. Do use high-quality images and videos. Use visually appealing images and videos to capture the attention of users and convey the message of the website.
5. Do use a consistent design. Use a consistent colour scheme, font, and layout throughout the website to create a cohesive and professional look.

Don'ts

1. Don't use too many coloexiturs or fonts. Stick to a minimal colour scheme and font selection to avoid overwhelming the user and creating a chaotic look.
2. Don't use too many pop-ups. Pop-ups can be annoying and intrusive. Use them sparingly and only when necessary.
3. Don't use auto-playing media. Auto-playing videos or music can be disruptive and frustrating for users. Allow them to choose whether or not to play media. If you do use it. Ensure to have the audio disabled and allow the user to play the audio if they would like.
4. Don't use small text or low contrast. Ensure that the text is legible and has a high contrast with the background to avoid eye strain and make it easy to read.
5. Don't neglect website speed. Slow website speed can lead to a high bounce rate and negatively impact SEO. Optimize images and use a fast hosting provider to ensure speedy load times.

By keeping these do's and don'ts in mind, businesses can create a website that is effective in achieving business goals and provides a positive user experience for visitors.