I am not a programmer by any stretch, a psuedo shell scripter at best.
I look at writing long code like the old saying "how do you eat an entire cow?" - one steak at a time.

I always break the code into smaller parts and then work on one part at a time until i get each part to work correctly. After I get one section of code to work the way i want, I start the next. After that one is done, i try to tie the two together. If they work correctly I go to the third and so on..

Just my thoughts