Espaliering is the art of training a plant to grow in a formal pattern, typically in a flat plane. Fans, double cordon, vertical cordon, palmetto, and Belgian Fence are common shapes but there is no reason to limit your imagination when it comes to training plants.
If you want an enjoyable weekend trip, visit Pearl Fryar’s topiary garden in Bishopville, SC ( a bit beyond Columbia SC).
Check out these good tips on espaliering fruit trees: The Art of Espalier Fruit Trees
Below are espaliered plants I’ve seen: