As a support main with an ADC duo, I found that my support style was overly aggressive for most ADCs and my own partner. Eventually I realized that with each new ADC I play with... I have to play to the ADCs strengths and hope he can follow through properly.
I dont know how many times I could count where the ADC was so overly passive about laning, leaving the support (me) wide open for anything.
When it happens NOW, I just stay behind my ADC and try to keep em alive as much as possible. If my ADC is just feeding at that point I usually just keep warding, playing safe and hoping to god your team fight will be good enough to carry on....
Im sure back in my starting days(s2) with support I was awful. Thinking that a support is a secondary mage... and its not.
With my main Janna, the ADC almost never dies now unless its just due to sheer inexperience.