I've been a fan of Mlynowski's since I read Milkrun, her first novel. She seems to have switched to YA full time.
In an article in Publishers Weekly, she says:
"Since Gimme a Call comes out next week, I thought it would be fun to ask a few fellow YA authors what they would tell their high school selves if, say, they had magic cells of their own. So on Monday I tweeted "Ever wonder what YA authors would tell their high school selves? (If they had magic cell phones that could call the past?) #gimmeacall." What started as a question to fellow authors has spread to their followers and their followers' followers. Search #gimmeacall for the full list of responses (over 1000 now), but here are some of my favorites (mostly written by YA writers. What, me, biased?):
@sarazarr: You are NOT FAT. You will be, but you're not now, so enjoy it.
@neilhimself: Dear 15-year-old-self, those comics you feel guilty for spending your barmitzvah money on each week will save your life one day.
@LaurenMyracle: Don't go on a pot run with Steve Campo. You will get arrested, and he will still take Leslie Prat to prom.
@nickearls: Dear HS Self: Do not try to impress girls by writing them sonnets. This tactic last succeeded in the 1620s.
Read the whole article here - and then check out all the Tweets yourself.