Here are some simple steps to avoid giving out your personal information:
Give Out A Separate/Disposable Email Address
Create a separate email address and give it to companies who needlessly request one. This really helps reduce spam. I use a disposal email address.
Give Out A Fake/Disposable Phone Number
Give out a fake phone number or use a disposable phone number.
Acquire And Use A Separate Business Address
Get a surface mail “business address” from UPS or the USPS (or a similar mail service in your country). You can then give out this address instead of your home address. This is a good policy for any business owner in general.
A UPS-style mailbox is preferable because you get a real street address — basically the address of the UPS store plus a “suite number”. UPS can also text or email you when your mail arrives. A small mailbox costs around $144 per year. A small Post Office (PO) Box costs about $122 per year.
Use A Different Name
If don’t want to give out your real name, you can legally write or sign your business name instead, and your business name can be something like “John Doe”. Details are explained in the book How To Be Invisible.
Use An Anonymous Credit Card
See this article for more information.