Hey man! I've run Crystal Beasts for some time and have a good experience in them.
ALWAYS 3 Sapphire Pegasus (sets good plays)
2-3 Topaz Tiger (good effect)
1-2 Amber Mammoth (okay effect, good attack)
1-2 Amethyst Cat (okay effect, descent attack)
2 Ruby Carbuncle (amazing card, amazing swarming!)
1-2 Emerald Tortoise (good defense)
2 Summoner Monk (Get Pegasus fast! Xyz well if planning for Xyz)
2-3 Dragon Queen of Tragic Endings (Good effect and easy to bring out)
3 Ancient City-Rainbow Ruins (greatest field spell ever.....enough said)
2-3 Crystal Beacon (just awesome)
1-3 Crystal Abundance (OTK finish. Killer plays)
1-2 Crystal Promise (Pretty good)
1-2 Rare Value (great draw power=great consistancy)
1-2 Crystal Blessing (great to get back from detaching in Xyz's)
1-2 Pot of Duality (Consistancy, Consistancy. 3 is too much, i run 2)
And ofcourse staples - monster reborn, dark hole, book of moon. Oh and DONT run heavy storm. Its counterproductive in crystal beasts because it is more against you. Run 3 mst instead.
I dont run any traps but you can if you wish. Just dont run too many. 0-5 is good i guess.
I hope this helps! Good luck! And Crystal Beasts are great, just be patient and they turn out awesome!