Your on your way now. Just keep those pins and holes cleaned out once in a while, and keep from slamming the halves together. It also helps to have a piece of 2x4 or some flat iron plate to close them on top of. This keeps everything lined up pretty darned well.
Thing is after you cast a pot or two full then load it up again, your wrist and arm will start to tire a bit, this is when things start to head south.
I know you can't see much of it due to the obvious, but I use several types of aluminum flat bar and square tubing to not only adjust for my molds, but to close them on top of.
The flat bar really helps to keep things aligned once I get into a good pour. It is also nice to have it set up under the spout to rest the molds on when pouring as well, especially when I am pouring a big batch of the 300gr bullets.