Every freelance bid should be customized. Remember, you are applying for a job and no one likes to see a bid and cover letter that was created as a template. You should also research the project owner. Do they have a website that you can refer to for more information? Did they give you an example of what they want the final project to look like? Also, look at previous projects they offered to see a trend. Relax and spend quality time on each bid. Use keywords from their ad to include in your bid. They want to see if you are paying attention to their needs. Finally, write about how your skills specifically match the requirements of the project.