For me, I continually alter saddle position in tiny increments. Sometimes raising or lowering it a bit or moving it forward or aft. To engage gluts I focus on Lemond's advice to scrape mud off the shoe at the bottom of the pedal stroke. Actually, I like Carbonfiberboy's approach to pull the feet back into the heel cup of the shoe. This seems to work a bit better for me. Ski instructors work at finding the right language or mental image to trigger the correct foot movements and weight transfer in skiing. The best mental image in pedaling will vary from person to person.