some also say to ignore the dog, and he/she will get discouraged and learn/realize the tactics don't work. i think that's way easier said than done.

some use that bitter apple spray you mentioned. some people just use water in a spray bottle. some people use the noise makers/pennies in a coke can for it. once you learn what your pet does or doesn't like, you can pretty much use it for all discipline. my dog hates a squeak toy i bought him, and i use it for discipline and it works really well.