Sift the flour and other dry ingredients well before liquid and fat. Really need to get you an old woman to show you how to cut the fat into the flour and roll the dough out right. I used to could make pretty good biscuits when I was younger, but I'm way out of practice. From what I remember keep the bowl, flour and lard/Crisco/whatever cold before, and while, you cut it in. I used one of those wood handled wire loop pie dough things to cut the fat into the flour. After adding liquid, barely mix it ,and compress all those little bits and liquid together and just BARELY kneed it enough to where you consolidate it. Gently roll the dough out, and minimize the times your roll it out again. I think it matters what you use to cut the individual biscuits with as well. If you use a dull edge like the top of a tea glass it compresses the edges where it doesn't rise right. I think you want to use a sharper edge like a actual biscuit cutter or a soup can/etc. This way its a clean cut and it rises as much as possible.

Good luck with it, you'll get it. Dang, I want a biscuit now.