So I primed and bottle conditioned my beer for about a month. Some bottles are really good beer with good carbonation and others, not so good and almost flat. Every bottle gives that whish sound and the release of gas when opened so I assume the caps were on good, but as I said some do not have much carbonation. I conditioned the bottles in temps that ranged from 70-80 degrees. This is my very first batch. How can I learn from this and keep this from happening again?