1. From scratch. Send me the details for what you're looking for and I'll get it done.
2. From icon. If you already have an icon prepared, I can create the favicon from this.
3. From logo. If you already have a logo designed, I can re-purpose it into icon-form for the purpose of the favicon. Generally, this means taking the primary capital letter of the company name, the same color scheme, and font as your logo.
Note — Source files and ownership rights are provided to you by default. There is no extra charge.