Check out
sniper's hide for ghillie info. There are several great threads.
I didn't do any special cutting. I laid my base out on the floor and cut the netting to fit it. For mine, I used a flight suit and cut the arms and legs short. I sewed on knee and elbow pads (foam and hvy canvas). I sewed a camelback bladder pocket into it. I also attached the netting entirely with shoe goo; no sewing. It's held up great - about 40-50hrs of stalking in it. A coupla bits need regluing, but it's hardly noticeable.
I'd change a coupla things: build it inside out so you have internal pockets. I wouldn't put in the camelback pocket; I'd just buy a light CB (mine is one of the bigguns. I would cut out a large chunk of the back a replace it with mosquito netting for ventilation. I met a guy who did that and it was very deluxe.
Also, go with light stuff for your cammy. The prepackaged stuff is nice, but 75% of it is too dark. Even if you're only gonna be in the woods get the tans, browns and pale greens. The darker stuff doesn't blend nearly as well. I ended up adding pounds of 'natural' jute to my suit once I did a coupla stalks.