I can't consume artificial sweeteners, so I like a dry cider also. I have bottle carbed using 22 oz bottles and have had good, consistent results with 1 tsp white table sugar per bottle. I rack the bottles first and then use a funnel to drop the sugar in, cap and then rotate a little to make sure the sugar is dissolved. Then bottle condition in my basement. It usually takes about 2 weeks to get a good fizz, and if it is too much-I cold crash in the fridge. I haven't had a problem with my dry cider-which is alot like the apfelwein recipie but have run into problems/geyeser/bottle bombs back sweetening with frozen concentrates. We drank a bottle from May last night that we forgot about and it had improved with age. I wish we hadn't drank most of it right away, as I think I may have 4 bottles left.
I've used carbonation drops too-but I think they have artificial sweeteners in them. The fizz they produce is good, but I used the low end of the recommended drops per bottle and aged a long time. The one awesome tip is filling a plastic screw top bottle so you can feel how carbonated it it. I used to fill 3-4 and go from there, but I don't have easy access to plastic bottles so I've just been opening and drinking to test.