Eric Kim wrote a fantastic PDF guide on Street Photography (available here).
This is one of the best book I read on photography. Yep, that good. Make yourself a favour and read it !
Point #43 is about taking shitty pictures...it echoes on what I was writing a month ago. I thought I was the only one to take bad picture! No! Hell! If even Eric Kim takes shitty street photos...maybe am I not that terrible of a human being ?