I'm quite certain you will be in for some loooong winded responses on the generalities of these 3 methods but in light of that here is a near correct example a teacher told me use a ball.
Taijiquan is like a Ball that will roll and bounce, recieving, redirecting and bouncing back force.
Xingyiquan is like a cannon ball, hard, direct and fas with force.
Baguazhang is like a ball of string, wrapping and unwarpping, tangling and binding in coming force.
Not a description in their totality but a good idea.
Earth, Air, Water, Fire, in the circle we conspire.