Rachelle Gardner writes an excellent blog and you should be reading it regularly. She delves into her email box today to answer one of the questions we hear a lot.
She buries a nugget of absolute wisdom in her reply: You’re not going to get free writing advice
By free she doesn't mean you have to pay with money. But you'll have to pay with either time or money. You either hire an editor OR you invest time in finding and participating in a good critique group or attending classes and conferences. One or the other, maybe both, but not NONE of them.
The deafening silence from agents to whom you send queries is actually saying something: you're not close. If you look at those year end stats of mine, you'll see there are those who hear from me even if I'm not saying yes. If you aren't hearing that, you're not in the ballgame.
Rachelle Gardner is a smart agent. Listen to her.