My first proper attempt at creative writing since I was 13, but it is heavily based on something I wrote all the way back then. Genuine response (hints and tips) welcome
Thanks to (darsi) for editing and advising

The sky was a dirty sodium orange, high above the tall brown silouettes of distant buildings. The recent rain had left a glossy sheen on the row of old semi detached houses on the opposite side of the street, and steamy, acidic puddles on the ground.
As I turned away from the window, I let the net curtain fall back into place. The bedroom was nothing more than a cupboard with blotchy painted walls with an empty chest of drawers in the corner of the room, squeezed into the space between the foot of the bed and the wall. On the bed was a battered old backpack containing a change of clothes and few keepsakes. I sighed and lent forward, snatching the bag up, swinging it onto my shoulder in a single move.
Another lighter sigh escaped my mouth as I stepped forward towards the landing and stairs. Clumping onto the landing and down the steps, the energy had drained from my legs by the time I made it to the bottom.

I unbolted and unlocked the door then gently pulled it open, taking the key out of the lock. Absent mindedly, I started to slip the key into my pocket then stopped. I looked at it and hefted it in my hand, I no longer recognised it. I set it down on the shallow window sill next to the door.
I turned one last time to look down the hallway and into the kitchen. Unbidden, memories of happier times started to flow through my mind, making my eyes itch and sting as they swelled with tears. Another deep sigh rolled out of my lungs and I recomposed myself. There was nothing left to do so I adjusted the bag on my shoulder and stepped out into the soggy night. Habit made mw turn to shut the door behind me. I halted half way through the action and considered it for a moment. A futile smile crept onto my face and I spun around and strode off, trying to feel defiant.

At the end of the path to the street, I stopped and looked all around me. Nothing had changed since I'd been upstairs. All for the better, that meant there would be no one around. I rushed into the street, just short of jogging, turning right and angled my path to the other side of the road where I would be shielded from the harsh street lighting. Houses who's tall walls were intentended to protect the residents little worlds I now ducked behind, trying to become invisible as I tramped down through mirror-like puddles. Slowly, as the low buzz of a helicopter became apparent, I froze. Gradually I lowered myself into a squatting position against a wall and cocked my ear in a vain attempt to discover where the sound was coming from. The noise dimmed and I started to relax. I took a couple of moments to compose myself, to stop my legs shaking, before carrying on my way. Faster this time, the less time I spent in the open, the better!

I made my way down a few more streets, trying to look inconpicuous, until at the end of one street I came to a tall security fence. It was only a simple chickenwire affair, easy to climb if you had the strength. The only problem lay in the flood lamps and mobile camaras mounted on tall poles in the long grassed field beyond. The bright light shone down making the gravel at the base of the fence bright white. Leaning with my back pressed against a wall, I waited until the camera on the nearest pole was facing toward its furthest extreme. I sprinted toward the fence, swinging my bag underarm with all my strength. As my arm stretched out forwards and upwards I let go of the bag and watched it sail over the fence and land on the other side with a soft scrunch. All of a sudden, I was on the gravel and had to slow to keep my balance. I jumped forward and flung myself as high up the fence as I could, hoping that the camera was still facing the other way. My feet pushed themselves into the holes in the fence and I forced myself upwards. My hands had trouble grasping at the links and I lost my hold as I tried to scramble up. I came to the top of the fence and swung one leg over and pushed my whole self over, almost in a hopping motion. I landed heavily and collapsed onto my side, making a violent swish as my body splayed across the gravel. I tried to stand but my numbed lower legs refused to respond properly as I staggered and stumbled across the shorter expanse of gravel on this side. I came to the grass, nearly where my bag lay and looked back the way I had come. Everything looked very much the same except for the sizable area of the gravel that had been pushed aside where I had landed, revealing the soil underneath. I looked up at the lights but couldn't see any evidence that the cameras mounted behind them had seen me.
I was still panting from my excersion and the adrenalin in my veins was making me shake. I took a deep breath, turned and started crawling through the grass towards the other side of the field.

I crawled and crawled and crawled for what seemed like endless minutes, trying to remain invisible. I didn't know how far I had come and I couldn't bring myself to stand up to find out. My hands and knees ached and felt raw, unused to the constant abrasive impacts they suffered on the firm ground and stiff stalks of grass. A buzzing sound drifted to my ears on the wind. Another helicopter, and louder this time! Closer! I filled with dread as the noise increased, the helicopter was coming nearer. I crawled on for a bit and looked behind me. I had left a long straight trail of parted grass, which would be easily spotted from the air, pointing straight to me. Panic started to rise through my body and an agitated groan escaped my lips. I only had one chance, I raised myself to a crouching position a made my way back to the fence as quickly as possible along the path I had taken, grasping at the tall grasses next to me trying to cover where I'd been. I was nearly at the edge of the grass when I could bare it no longer. The helicopter sounded almost on top of the field and I lay down, pulling at the grass again, trying to cover myself. The helicopter grew louder still and the grass around me started to wave as the breeze caught it. My eyes watered, my gut squeezed and I wanted to be sick but I hardly dare to breath. The beating rotors stopped getting louder. It had stopped. I was too scared to find out where it was in case it was directly above me. My breathing became even more panicky and I was sweating from more than just my excersions. In an instant the world felt as though it was ripping itself apart. Machine guns on the helicopter had opened up and I screamed as I heard the crack and splat of heavy rounds hit the ground. Then they stopped just as quickly as they had started and my breathing halted again. Nearby was someone screaming in pain. No words, just a suffering wail. It continued until the sound of the helicopter deepened. It was coming in the land and the person (it sounded like a man) now added absolute terror to his voice. It filled my head, the ground shook as the machine came down. I heard people jumping out and the man screamed louder. He became muffled for a second then I heard a slam as a door on the helicopter closed. The screaming stopped like it never existed.
The sound from the helicopter engines raised in pitch and it took off again. Moving away from me, it grew quieter and quieter until it was gone. I didn't dare move, I curled up on the ground, scared, my eyes scrunched closed. Eventually I became calmer. I still had to cross the field.