I loooooooooove my Earth/Fire Dom. It's like being a Blaster with Controls. Great control, great damage = loads of fun.
In Earth control, you can definitely skip Salt Crystals and probably the single target Immobilize. Other than that, all of the powers are awesome. 
@Dante EU - Union Roleplayer and Altisis Victim
The Militia: Union RP Supergroup - www.themilitia.org.uk
I would go earth/fire/fire. Earth is already practically god for control, it doesn't need any help from a secondary. Therefore, the secondary is for damage, and fire has plenty of that. As a bonus, combining the fire secondary and the fire epic lets you use embrace of fire on fireball and RoF, further boosting your AoE output.
In earth control, you can definitely skip salt crystals, totally not needed. Stone cages is also not mandatory, since you can use quicksand instead (which you'll have anyway, since it is awesome) to limit wander after stalagmites. I would take everything else - stone prison is lower priority but still useful to immob EBs, and every other power is a core power of some sort.
@MuonNeutrino
Student, Gamer, Altaholic, and future Astronomer.
This is what it means to be a tank!
sounds good, i had a feeling earth/fire/fire was gonna be the response id get, i do like the boost to fire damage from fire assault. ty for the responses. What alpha slot u think is good since i have consume for +end and embrace of fire for damage? maybe the rech alpha?
Thinking of making a Earth/something dom. for teaming/sf/tf's and good overall damage output.
Whats a great secondary? btw i already have a perma mind/psi/mace and fire/earth/fire dom. so psi is outta the question.
Been looking at thorns...hows it perform ingame?
And whats a good patron pool for this toon? i have used the fire mastery b4 and enjoy it for rain of fire/self rez/fire shield.
Also what powers in earth control can i skip/not needed.