I was told to not use the rounded sides of the iron and alway press from the tip of the iron. They also said to open seams at a 90 degree angle from the grain of the fabric

This is so true, if you press your block from an angle, your block will lean that direction...
I was taught to place it laying nice and straight on the ironing surface, and press straight sideways or up or down. If the block is placed at an angle, you are more likely to press straight up/down/to the side and distort it.

No steam, lots of starch, press and lift. I use Mary Ellen's Best Press starch. Don't ask me how I know.

The only times I've had major trouble/problems with distortion is when I've used starch/sizing.

Am I supposed to wait for it to dry before trying to press/iron?

I soaked the piece (didn't mean to, but it got pretty soggy) and then was trying to "shape the piece" by hand before applying the iron to it. it got quite a bit bigger.

Multiple light sprays works for me. I usually spray twice on each side.

Pressing your fabric wet, whether it is water, starch or sizing will cause it to distort. That is why I spray and then let it dry, so the fabric holds it's shape. Hanging wet doesn't seem to distort it, as long as you dont stretch or tug on it.

Aside from starching, having a firm pressing surface is supposed to help a lot. Sharon Schamber has a video on Youtube showing how to make your own. A soft ironing board is not nearly as good for pressing blocks.