Graff and Birkenstein (They Say / I Say) offer some good advice in framing, or sandwiching, a quotation. They suggest when quoting someone to follow these steps:

1. Introduce the person and their position on the issue.
2. Write the quotation
3. Explain the quotation
4. Respond to the quotation from your own position and perspective.

Also, don't just choose any quotation. Be sure to choose one that fits into your own argument, whether it supports your argument or opposes it.