What advice would you give a customer looking to hire a provider in your area of work?
My biggest piece of advice would be: don't hire the most inexpensive designer. Look at websites and portfolios and look for a style you love. Many clients come to me not knowing what they are looking for, but say they will know when they see it. That is true, but you can only get to that point if there is good communication between the designer and you. I do a creative brief which allows me to gather valuable information from you to make the finished product uniquely yours.
I charge by the hour so everyone knows what they are getting. I am VERY honest and deliver the best for your money.
So when hiring from Thumbtack or any other online service, do your homework and look for a designer that is a great communicator, has experience in the area you need help with and supplies you with phone numbers to references so they can give you their experience with that designer. Most importantly follow your instincts...if something doesn't feel right, don't continue. Marketing and graphic design is a team effort between the client and the designer. Good luck!