I have found chore charts help hugely with the whole "how dare you ask me to do that" response. We used it daily for about 6 months and then miracle -- kids would do what I asked. Now if there is a non compliance response, I suggest we get the chore charts out and that ends that. For clothes I think marking them is a good idea but realistically it won't end it. I forget how old they are but I think it is a "you guys sort it out" starting at age 8 or 9. And if they fight the item goes into a penalty box (for like a week). I don't like being the go between with my boys (not twins). GOOD LUCK!
DS #1 Summer 05
DS #2 Summer 07