There are two types of juice extractors that are pretty common one is a basket type where the pulp builds up inside the spinning basket and you have to stop and empty it every now and again, the other is the continuous type where the apples (or whatever) go in the top and the juice runs out one side and the pulp is thrown out the other.
Basket juicers are much better at extracting the juice, a bit more stuffing around but very efficient, if you want to get just a bit more of the juice out, just before you stop to empty the basket pour a glass of water down the apple in hole, it will travel through the pulp and rinse out a bit more juice - it might be a good idea to change your juice collecting container, so you end up with well first running's and sparge water in separate containers. measure gravity and taste to see if you want or need to blend them together.
Continuous juicers leave a lot more of the juice in the pulp, if you run the pulp back through the juicer you will get quite a lot more juice, you could even add a little water to the pulp before reprocessing it.
Making cider from scratch can be fun, I made a batch out of Fuji apples once that was pretty nice, stopped the ferment early to keep lots of that Fuji sweetness - shame its so hard to get real cider apples in Australia I would love to be able to play around with them.
Mark
