I've spoken to folks about their experiences with commissions, (from both the artist side and the buyer side.) Most have tilted towards the positive...but when they go wrong, they really go wrong. I once did a commission for a guy who had been collecting some work and had a specific idea about 2 large canvases representing the nature of man and the nature of God. It took a few months to complete the work, but I was pleased with the results. The problem: the guy went AWOL. No longer returned my calls or the gallery calls. When I finally did reach him, he said "I can't go through with the commission." That was it. Ultimately, (after a few years), the work sold and I got lucky. But some artists I've talked to haven't been so lucky. Make sure you ask many questions and even put together a basic contract to protect yourself. This applies to both creating and commissioning work.
That said, I've just completed a work for friends that I wanted to share. I know them very well, so working symbols into the painting was a little easier. Matt is a big fan of all things Boston, so I started there. I wanted the work to contain both an overall feel and many intricate little stories that take place when you move closer. I've included the finish piece along with the image of the Green Monster that inspired the piece.