Start with himself
From Torg Adventure
Ben realized he could change himself. He finished his dinner, excused himself from the table, and went up to his room. He looked at himself in the mirror, noting the slouching shoulders, the clunky glasses, the tousled hair, and the zits. He started slow, saying, "I want to have 20-20 vision."
Everything in the room went fuzzy. He took off his glasses and everything came back into focus. "I want no more zits and good-looking hair."
His face cleared up. His hair got a little longer and much shinier and well-groomed. Ben smiled with fascination. "I want to be in good shape physically."
He could feel his body shifting. It was a little painful, but mostly just weird feeling. When he looked in the mirror again, he stood straighter and he could see muscular definition in his arms. He lifted up his shirt and marveled at his solid abs. He dropped his pants and ran his hand down his muscular thigh. Then he pulled his whitey-tighties down. "I want an eight-inch dick."
Before his eyes, his small, flaccid penis lengthened and thickened. It hung impressively between his legs. Ben beamed. "Now I just need someone to fuck."
He was startled at the knock at his door.
Who was there?