Finishing Touches

From Author Wars - https://authorwars.com/publications/finishing-touches-13572.html

Overview:

Title: Finishing Touches
Author: Thomas Tessier
Year: 1986
ISBN-10: 0689117469
Publisher: Atheneum
Price: $14.95
Pages: 243
Binding: Hardcover
Type: Novel
Title Reference: Finishing Touches
Notes: Cover artist credited on inside front DJ flap; it actually says "Jacket design" and there is no signature on the cover, but artwork is in the same style as Steinberg's other credits on ISFDB and so is likely by him.