1. Intermediate Mediation: Filling the Polyhedron
This sounds a bit intimidating, and it likely is a bit imposing until you get the hang of it. In this case, you'll be starting off by creating a tetrahedron, pictured below.
After you've gotten the hang of this, your next step will be to do this with a triangular prism, then cube, and then so on and so forth. Each step up the chain will get markedly more difficult to do, but that's part of the growth process.
2. Intermediate Meditation: Filling the Balloon
In this exercise, you'll take everything you've learned and now turn the object you fill into something you can interact with.
This exercise works just like the name implies. Create a limp, unfilled baloon in your mind, then fill it with a substance. Watch how it grows in your mind, feel its weight, let air out, put more in. Try to keep it from popping. ;)