Email Blast- Do a daily email blast to all customers you did business with that day them to write a quick review for you. You should also be following up after cross selling, giving promotional offers and asking for referrals.
If you have an automated emailing system such as Constant Contact, Infusionsoft, or have a CRM that has email and text capabilities built in, you can easily add this email to your email chain or add this info to an existing email.
Of course, we do have a great automatic email system as well!
Below is an email chain we have found works extremely well.