1. Define your niche: Identify a specific area of writing that you are passionate about and specialize in it. This will help you stand out in a crowded market and give you a unique point of view.

2. Develop your skills: Read widely and practice writing frequently to hone your skills. Take writing workshops or courses to learn more about your craft.

3. Know your audience: Understand who you are writing for and tailor your content to meet their needs and expectations.

4. Research extensively: Ensure that you have a strong understanding of the subject matter you are writing about. Research thoroughly to gain a deep understanding of the topic.

5. Use proper grammar and punctuation: Ensure that your writing is error-free by using proper grammar and punctuation. Use a tool like Grammarly to help you catch errors in your writing.

6. Write with clarity: Write clearly and concisely to ensure that your message is easy to understand. Avoid jargon and complex vocabulary when possible.

7. Be original: Write original content that is unique and engaging. Avoid copying or plagiarizing content from other writers.

8. Use SEO best practices: Use search engine optimization (SEO) best practices to ensure that your content is search engine friendly and ranks higher in search results.

9. Develop a portfolio: Create a portfolio of your work to showcase your writing skills to potential clients. Include articles or samples that highlight your strengths as a writer.

10. Network with other writers: Join writing groups or attend events to meet other writers and learn about new opportunities. Connect with other writers on social media platforms like LinkedIn.

There you have it, 10 tips on how to be a professional content writer. Remember that practice makes perfect, so keep writing, learning, and developing your skills. With persistence and hard work, you can become a successful content writer. Good luck!