I think the biggest tip I ever got for dealing with teens was to stay calm. Obviously easier said than done sometimes but it does tend to work. I don't argue with my two, if they are moaning about a perceived injustice or the unfairness of something I simply say "oh dear, yes that's a shame' or 'I know life is a bummer sometimes eh'.
When they were about the same age as yours I got fed up of hearing my own voice sometimes so I implemented the word no. If I asked them to do something and they didn't do it, I didn't 'nag' or shout, I simply did it myself. The next time they asked me for something (food, drink, money, lifts etc) I simply said no and carried on doing what I was doing. It didn't take long for them to cotton on (although I did tell,them why if they asked) and fairly quickly life became simpler.
As they got older I stopped going in their rooms. I told them I was fed up of going on about it and that if they wanted their rooms cleaned they would have to make sure they were tidy first, if they didn't put washing in the basket then it didn't get done. More than once I've watched them go off to school with dirty crumpled clothes because they 'forgot', but it didn't happen often, they soon get the message. If they complained that something wasn't ready (like pe kit) I simply said calmly 'oh dear, if you wanted it washed it should have been in the basket'.
It's hard to stay calm and to step back from babying them but the results are so worth the effort. My now 18 & 21 yr olds are lovely, independent, respectful boys.
Although of course they may well have turned out like that eventually anyway. I like to think that my style of parenting helped smooth the way.