I found that when I started to write (and believe me I in no way think of myself as an author, yes I have had a book published and no its not modesty. I feel that I was just a bloke with an idea and i jotted it down). Back to the point I was saying. A good tip was not to listen to what people told you, you get a lot of good points and a lot of bad points and in the end it drives you scatty...well it did me so what I did was to write the piece as best I could and then compared it with other published works (same genre helps) then after I was happy with it did I let others read it and judge it, and give me advice, I coould then argue for and against as to why I wrote it like that or put that piece in.
Basically I would just go for it write what you want, listen to your heart as well as in your head.
WHAT THE HELL AM I GOING ON ABOUT! It helped me anyway, you should see the rubbish that I have written.