Unfortunately, theres no tried and true way to win immediately with your extra turns, but there are ways to pull yourself far enough ahead in life and card advantage that your foes have no hope but to concede
Champions of Kamigawa Kiki-Jiki, Mirror Breaker Kiki-Jiki, Mirror Breaker was the first card to create a temporary creature token that is a copy of something
As long as you have seven cards you can draw even more
Once played, you can use First Contact, which puts a Quest Counter on the card every time it or another creature with power 3 or less enters the battlefield
Black Gravecrawler 7.6 Bloodsoaked Champion 7.4 Dread Wanderer 7.3 Gutterbones 7.2 All recurring 2/1s for B
Diaochan, Artful Beauty and Etali, Primal Storm are other strong candidates