I always think of August as my jam month, because blackberry is my favorite. I freeze both strawberries and raspberries as they ripen, and use them as well. As I'm munching my morning muffin with jam (made by a friend) I thought we might share some combinations that have worked well.
Peach, ginger, vanilla (real light on the extras) - this is my friend's and wow is it good
Blackberry with about a half cup of dark rum = Rumbleberry
Blueberry and raspberry = Blazberry
Raspberry with a stick of 70% cocoa added as the berries cook down
Peach and banana with some chopped maraschino cherries swirled in at the end