Best Answer: Using margarine or shortening will result in a less flat, less crisp cookie, allthough you're sacrificing flavor. When you use butter, make sure its not rock hard, but not too soft.You don't want the butter to melt into or absorb the flour before it bakes.You can substitute half the butter with shortening or margarine (make sure it's cool). I think the trick is using less sugar and or replacing some of the granulated sugar with brown sugar which has more moisture and keeps cookies softer.If you over-stir your cookie batter, it will also result in a tougher cookie.est Answer: Using margarine or shortening will result in a less flat, less crisp cookie, allthough you're sacrificing flavor. When you use butter, make sure its not rock hard, but not too soft.