Not really. You keep your fingers crossed if you want something to happen, if you are making a wish and you cross your fingers to give your wish more power or if you are telling a lie! Some people believe that if you cross your fingers while lying, the lie isn't bad or isn't a sin. Hmmmm!
So if you have a job interview and someone asks if you got the position, you could say, "Not yet but I'm keeping my fingers crossed."
"Touch wood" is something that you say when you don't want something to happen. "I haven't had a car accident yet, touch wood!" Then, of course, you touch something made of wood. If there is no wood around you can always touch your head! :)