Patching and Plastering - Help with stomping my ceiling

I am in the process of finishing my basement and I am now ready to stomp the ceiling. I have the topping compund and round brush for the pattern that I am looking for but I am not certain how thin to make the mud and what is the best method of putting on the ceiling. I have been told to use a roller, but when I tried that the roller would not pick up the mud very well. I am also uncertain how thick to put the mud on. I have also tried putting it on with a 12" tapping knife in a small area, but the mud cracked when it dried. I would assume that I put it on too thick. I tried to use the edge of the knife to judge the thickness of the mud and it was about 1/8". I also have a gun to spray it on with. I am not sure how well that will work though. Any light that you could shed would be greatly appreciated.

Thin the mud down with water until it's about the consistency of a soft serve ice cream, and them just mash your brush into the mud and then on the wall, I think this will give the desired results. Coops or Tightcoat should be around here today and have some additional tips for you. I don't get into hand applied textures, too time consuming.

Really depends on what look you are after. I'm assuming you have a stipple brush(since you said it was round). I'm with Awesomedell. Thin your mud down and dip the brush into the mud. What look do you want? Are you going to knock it down? Let us know.

The only thing I would add is I like to let the texture dry and not knock it down. Then use a trowel to shave off the points. Doing so seems to leave a bit of a two tone effect. It's a little different from knocking it down. Something I haven't tried but that might be attractive is to paint the lid, texture it, let it dry, paint it some desired color then shave the points. I think the edges of the points would grade gradually from the paint color to white and it might look good.
Eventually this will have to be painted but it might look good for a while before it's painted
This is more than you asked about but the words are flying off my fingers.

One more hint- soak your round brush if it's new, in warm water, form it to a flat version of the round brush, weight it down let it dry like that. Your new round brush is now ready for use. Good luck

Using a roller will speed the process up. You need to thin the drywall mud to a thick paint consitency. The thicker the mud the heavier the texture, the thinner the mud the lighter the texture. Once you experiment with it for a little bit you can become as good as a pro. It doesn't take a lot of skill but it is kinda messy.
If you have a hopper gun you can thin down the mud a spray a texture on the ceiling - orange peel if you just spray or spray and take a broad knife and knock down. Don't know if you could spray and stomp or not but you can try it and find out.