use one cloth to apply (polish) and one to wipe off (buff). also you know youve polished enough when your polishing so hard that its starting to actually buff off (then that means ur wiping too hard and prob need more polish)... also, try using sealent as well as wax i found my car too stay clean for about a month that way! (sealents meant to last longer but im a bit of a noob when it comes to applying it, so surely once im good at it it'll last longer)