It took me almost a year before I felt my point were ready to hunt with and they are still twice as thick as those produced by the more elite members of the board. I'll give you the advise that I would have given myself if I could have. I don't know if you suffer the same mistakes I was making, but it's good advice regardless.
Abrate- Get rid of those sharp edges, especially on man made glass and obsidian. If the initial energy of your "bop" is being robbed by turning a thin sharp edge into powder you'll never get a good feel for the amount of force you need to drive the flake you're attempting.
Slow down- It's really fun to smash rock, period! It's easy to get carried away. Stay calm go slow. Remember your trying to smash this rock in a very deliberate and almost delicate way.
Understand a crystal matrix- This one's kinda out there, but it's something I noticed and it helped. Just because the steps(or other undesirable defect) is on the other side of your preform it doesn't mean it won't affect a flake taken from the opposite side. If I screwed up the edge I was working on, I just spun the piece and started pounding that side without doing anything to clean up the area I just butchered. Through trial and error I found that you have to work the piece as a whole not just move from spot to spot.
The forces that bind a crystal together are unique and amazing. It's why quartz will give a flash of light and an electrical current when broken. It's has magnetic components as well, as does most electrical phenomena. When I started thinking of the binding forces as being magnetic it seemed to improve my attempts greatly.
So,... if you have a bulky area, it is pulling the all the other thinner area toward it with more force. This area of more mass can cause a flake to take an unexpected drive, terminate and form a step, or countless other undesirable things to happen. This is where working the piece as a whole comes into play. After every flake, look the whole piece over again to see what's changed. Check your centerline, looking for the largest areas of mass. That's where your next flake should come from, because that's where the greatest force that holds everything together is coming from. That way every flake you take off requires a little less force to come off than the one before.
Bear in mind I don't know if this is actually what is happening from a physics stand point, but this line of thought brought about my most noticeable improvements and me finally feeling like I'm starting to get the hang of this.
All rock is different- In the beginning it helps to have a one that behaves as expected. A uniform consistency and a medium to light hardness is what is best to learn on. For me the clearer obsidian and regular glass fractured too easily and just seemed to want to crumble. The texas chert was good until it came time to pressure flake because it takes so much force to do so. I had my best results early on with dacite, noviculite, and keokuk. All are easy to flake without having the tendency to want to crumble.
This was a hard skill to even begin to develop, but that's why I like it. I've alway been the guy who hears "What, you got another new hobby?". When I get good at something it gets boring and I'm on to something new. With the knapping and bowyering however, I don't see that happening any time soon.
I could keep spouting obscure hard to follow advice all day, but that would contradict the "taking it slow" tip. Keep us posted on your progress and keep asking questions.