Also once put together let them stand abit before putting them back in the car. I always let mine sit over night, but sometimes you can't do that. If it is a rebuild, I think the biggest key is to make sure all the oil is cleaned out of the shaft and off the screw.
As far as shock rebound goes. I always built mine to slightly rebound, I built them basically the way described above. But last year at the midwest gas champs at CRCRC Mike Truhe was in our tent and one of the guys I was with ask him about building shocks, he built one for us. He filled it to the top, put on the bladder and capped it. It rebounded dam near like it had a spring on it. He claimed that is the way they build them. I've tried it and I liked it, it made the car react alot faster that is for sure.