The title tag is one of the most important part in the website which help to get good result (ranking) in the search engines.

How to write title tag?

Start with the most important keyword in the title Search Engine Optimization /title under your webpage head tag

Write maximum 65-70 character in title.

Title should be relevent of the web page.

Example: If your website related to Search Engine Optimization. Your keywords should be Search Engine Optimization.

This will help to get top ranking and traffic in the web site through the search engines.
You can start with your brand or company name but Keywords should be relevent of the page or service which will help you to generate business and ROI etc.