Hey DND,
I'm not particularily fond of baking powder/soda, so I try and avoid it when I can.
When I make scones, I use a weird technique. If you're new to baking, you might not know about puff pastry, but there are a zillion ways to make it. One way is the "Blitz" or lightning method, where you cube your butter and mix it into the flour, add your water, and make a right mess. Then you roll it out, fold it, and repeat a few times. It rises quite well--not as good as classic puff pastry, but still quite well. What happens with puff pastry, is you have a thin layer of dough and a thin layer of fat (usually butter), paper thin layers,actually. When you bake, the water in the dough turns to steam, but the fat layers prevent/slow it down from escaping, giving you a decent rise. As it continues to bake, the steam eventually escapes and the fat melts into the dough.
So I use this technique with my scones. If I'm in an extravagant mood, I'll whip some cream, and fold this into the dough--adding another shot of air, which rises when the heat hits it.
Being a Canuck, I confess I don't know much about "biscuits", but it would seem that the doughs of biscuits and scones would be somewhat similar.