I get this asked a lot by my freelancer and photographers friends asking for the process for Visa Application especially for Schengen Visa. So here I have attached a sample cover letter that I use for Visa Application. Also mentioned are some of the documents that you must submit while applying for visa.
Do print the visa letter on your business cover head to add onto the authenticity of your profession and the letter.
One can apply for an MSME certificate online on their official website. Likewise it would be advisable to get a GST certificate done to authenticate your profession/business.