The best method to facilitate funding transactions for an accredited investor on the Fundable platform is to use the platform's built-in investment management tools. These tools allow for easy communication and documentation sharing between the issuer and investors, and also provide a secure and compliant way for investors to complete their investment transactions. In addition, Fundable's platform also allows for the use of electronic signatures and electronic funds transfer for added convenience and security. It's also advisable to consult with a legal advisor to ensure compliance with the regulations.