How to select your crystal and shape ...
First things first:
Breathe and Connect Into Yourself, Try to Quiet Your Mind
Identify what you feel you're missing before looking into what the stones can provide you. This will help you figure out what's going on within yourself before depending on outside sources. From there, just let your intuition choose what's best for you.
The seven crystal systems are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. It is also important to feel what shape you are drawn too.
Some people like the feel of a Raw Crystal straight from the earth.
Some like Polished, smooth and calming and brings out different elements that can be hard to spot without being polished.
Then you have the other Shapes witch can be used in Grids and Energy work.
We suggest you start with around 5 or 6 different crystals or stones to really become familiar with them and their different positive influence on your emotional well-being. Naturally, you'll want to expand your collection, and this is when an in-depth book on crystals and gemstones can come in handy.
Have Fun With The Shapes, See How They Feel For You!