Provide a clear example of a similar job you have done in the past.
I work at a financial industry by creating Excel macros and reducing the amount of human labour required to mantain and share data.
Proposal:
Hello!
My name is Tomas and I am an data automation expert.
I may charge double of what others normally charge, but I might provide you with the possibility to automate an otherwise manual process and save you some money in the process.
Please send me some details about your project and I will analyze whether this is something that can be automated and reduce costs.
Best wishes!