Ranking promo help

Hey fellas!

I've been stuck in bronze and I am having a hard time with promos. Is their any trick behind it? Whenever I get in one, the matches become super tough =/ afk's, ragers. All that good stuff. If I ever enter a promo with a 3+ game winning streak I just know I am not going win the series =[

Also, with the adc changes for next season, is their just no reason left for playing

(I know but I love gems! They're outrageous!).