I'm often asked, "What's your favorite thing to put in cider?"
With fall comes apples and with apples comes homebrewers carrying bottles of cider which tastes of paint thinner and nail polish. This is a basic mistake and it doesn't take much to put some great flavors in cider.
To make it good you need to first understand what is going on in there. With beer, we are breaking down starch into sugar, so the yeast can eat it, but the breakdown is not complete so there is a lot of residual sweetness. Apples are made up of much simpler sugars so the yeast is able to consume nearly all of it. The result will be a solventy and dry concoction which is not drinkable.
Here is the way to hear cheers and win awards in cider. Take your five gallons of fresh juice or cider and freeze two gallons. Add a Camden tablet and sugar to the other three gallons until you have a OG of around 1.070 to 1.080.
Add your yeast. I have used ale yeast, cider yeast and wine yeast and the wine yeast has worked best for me. The others seem to fizzledick around and then crap out before it is finished. You want a yeast that will get in and get things done in cider.
Then just wait until fermentation is finished and the FG reads 1.000, or around there. Transfer to a boil kettle or a spouted vessel.
At this point the cider will just be a mess. It will taste absolutely horrible and you will be tempted to dump it. First, add the two gallons of fresh cider you have saved, this will bring the apple taste you are looking for back. Give it a stir and taste it, then start adding sugar until it tastes as sweet as you want it. I like it crisp, but not to tart. If you want something more like a pie then add apple pie spices. Everything is done to taste so the sky is the limit. I guess you could make a carmel appletini cider if it floats your boat.
When the cider tastes exactly how you want it to it is time to arrest fermentation. Potassium sorbate is supposed to work but I have never had much faith in it. I normally heat my kettle to pasteurize the cider and then keg it to add the gas back. If you don't have a keg system then get with the program, or just have still cider.