Back to school clothes shopping?

I have three kids going to school this year, a 1st grader a kindergartener and a pre schooler. What is a good back to school list? Like how many jeans, shorts,ts and stuff. Do you think 10 complete outfits and a few extra shirts? Normally i would just take the 2 and go buy what ever but now with 3 i think its time to be more prepaired