Needing to make a fondant couch for a cake topper, don't have an airbrush, is there a way to make it look more rustic other than just coloring the fondant brown and shaping it? and is it just shaping one big piece of fondant for the most part?... not sure how to do the arms of the couch?

How about brushing a little cocoa on the fondant?

good thinking thanks!

Make the couch out of RKT.  Depending on the size fondant might be too heavy. Then cover RKT couch in fondant and either paint or imprint it. Or both. For a really rustic/old look you could also cover it in fondant and then roll and tear more pieces of fondant which you can randomly attach to the couch so it looks like it's ripped.