I worked with Don Taylor at a marketing agency; I was the lead web developer and he was one of our creative directors.
There are many traits I could recommend him on, but two in particular stand out to me: his breadth of experience and his quality of workmanship.
First, he has worked in the industry for decades now in many different settings and media. He knows classic design and current trends. He knows logos to billboards and packaging to web pages.
Don cares about his craft and he wants to get things right. He would give us precise feedback when we implemented his designs. He would explain what he wanted and the principles behind them. He helped us produce our best work.
I would happily work with him again and recommend him to others.