Less is more.
- Put an expiration date on your deal. If they call you after that you've already set the expectation that it's going to cost more.
- Put a phone number on it and always answer your phone.
- "Properly licensed and insured."
- "Check out our awesome reviews on Google, HomeAdvisor, Thumbtack, and now Angie's List"
The last two are on everything our customer sees. The last one gives you credibility. If you don't have reviews consider doing a couple driveways for free in exchange for reviews.
I'm 2 years in and Saturday morning I'm washing a new neighbors driveway in exchange for a review on all 4 sites. Less than an hours worth of work for for 4 positive reviews that are worth their weight in gold.
Oh and the little cartoon head is STRAAANNGE