Pick Ice Patch up ASAP (Or well, BIB first, but then that), it's the main power of /ice. Also, I dunno about getting bitter freeze ray, and if you do get it, I'd suggest dropping it later when you get access to the hold from your secondary (and epic, possibly), since the activation time is so damn long.
My personal picks from ice/ice (as a levelling build, not a respec one):
Ice Bolt
Ice Blast
Aim
Freeze Ray
Ice Storm
BIB
BFR
Blizzard
ChillBlain
Ice Sword
BU
Ice Patch
Freezing touch
Leaving room for SJ, stamina, and then 2 pool powers, possibly hasten+acro or aid other+self, and 4 epic powers.
1 power that i just got on my nrg/ice.. frozen aura. I havent slotted this yet, the idea behind the power is pretty nice (tiny aoe sleep) great for solo. Animation is just awsome (footstomp with ice), though im not convinced this power will be used by _any_ /ice blaster. I wanted to use that power for first attack (CE doesnt break sleep) before popping Ice patch.
MaX got the nice list of good powers, freezing touch is a very fast melee spam hold power with nearly the same damage as BFR. Going Elec or Fire epic you can replace the BFR for the epic hold, so you can range hold a boss.
Or if you more 'debt-risking', take stealth. Run in the group, put CE on, hit Ice patch, FR/FT on the boss. BU/Aim, ice storm, blizzard. Basicly nothing can survive that 
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Thanks for the responses. Looks like I have a solid build so far and can get some great powers in future.
From the primary, I tried BFR but dropped it after a couple of levels (slooooow animation): much better to stack FR and use Freezing Touch. I found Frost Breath to be an OK power, at least in the 20s (before Blizzard). With Aim+BU it does some decent AoE damage. From the secondary, I used to hate Chilling Embrace, but found it more and more useful since you end up blapping a lot (slow and -dmg). I used to have Frozen Fists for toggle-dropping but have dropped it now. Otherwise I found all /ice powers to be good (including Shiver) except for Frozen Aura (really can't see how anyone can use it much in the 40s 
). Concerning Epics, I preferred Force because of the nice shield, the panic button (PFF) and of course, Force of Nature (a mini-Unstoppable). Epics really depend on playstyle, i.e. do you plan to PvP? do you feel you need an extra hold? do you want a snipe? do you want a concept toon? do you die a lot a want a self-rez? etc... And definitely take Stamina and Hasten.
Enjoy! 
CoX 50s: <ill/rad> <ice/ice> <fire/kin> <grav/sonic> <ice/storm> <earth/kin> <kin/elec> <cold/psy> <thugs/dark> <fire/dark> <dark/elec> <night widow> <EM/ninj> <mind/icy>
As I've already got for Force with Prox (my Energy/Energy/Force Blaster) I wasn't looking to use it again. I like the sound of Fire's self rez and hold.
Just to say a word for BFR, I find it works really well on bosses, because you can BFR from a distance, then as you close you FR, and the boss is held by the stacked hold.
I hit 22 yesterday and got Bitter Ice Blast.
It's so nice to have a power that looks dangerous rather than you just throwing a snowball!
At 24 I took Ice Patch, and it's a lovely power.
When I first got it I was trying to run into spawns and put it down a la my beloved Nova. However once I realised it's much better to wait for the Tank to take aggro then place it next to him, it started working really well.
Best use for Ice Patch on a blaster? Drop it on a corner near a spawn. Shoot at spawn. Run around corner. Spawn follows you. They all fall down. Kill helpless baddies. Repeat.
This works like a charm solo and on all-squishy teams. And you soon get to learn which mobs are resitant to knockdown [img]/uk/images/graemlins/tongue.gif[/img]
Icen, my wee tech-suited Ice/Ice Blaster, has got to where she needs to be at 20 - 2 ranged blasts, a ranged hold, a melee move, BU and Aim, SJ and Stamina.
However, now she's on the way to 22, I have no idea what powers to pick. Any Ice/Ice veterans have any advice? The guides on the US site are for i4.
I know Bitter Ice Blast and Bitter Freeze Ray are worth getting, how about any of the others?