What makes a good writer?

You finish reading a book and come to realise that wow, this book was incredible! Then you look at the piece you're currently writing and come to realise...
wow I'm pretty terrible aren't I?

DO NOT DESPAIR! Here is a cure to all your writing ailments.

Want to hear it? (rhetorical question, of course you do!)

Well here it is. 1. Do not think too hard.

Writing should flow out of you, it should be natural. Thinking too much won't help too much. Your first draft should be whatever the hell come into your head at the time of writing (concerning your plot of course, you're not going to put kittens because you thought of them in a horror story). When you come to edit, that's when you should think the hardest. Writing always sounds better when it's natural.
Here's an example. First of what not to do, and then what you should do.
There is a light in the distance... (OMG let's spend ten minutes thinking of what to write next)!
^Do NOT do that.

There is a light in the distance. Its tendrils shoot up to claim the darkness in the sky. Eyes are drawn to the light, sparkling eyes drawn by wonderment. There has not been light in this city for many years, and it was a source of legend nowadays. The legends of light always spoke of things, strange things, and what the return of light would bring. The others were here.
I wrote that in the space of a minute, spending little time to think. See how the writing sounds natural? A writer shouldn't have to think too hard. Just like how the best soccer players in the world don't have to think too hard about how they want to get the ball in the back of the net. Your reader will know when you're thinking too hard through your writing and it will definitely damage the quality of your written work.

Another small thing which I'd suggest in your road to becoming a good writer is:
practice.
Practice makes perfect.

And there you have it, the two things which make a good writer.
1) Do not think too hard
2) Practice

Take care!