Zon:
Back in 1.09 and the days of the Buriza zon, it was popular to use Guided Arrow, Multishot, various passive skills, and the stronger freezing arrow (don't remember what it was called, but its the last one in the cold line, it freezes groups of enemies instead of just 1). You can use guide arrow on single targets and never worry about missing (don't max it, 1 point is fine), it will always hit unless it is blocked (as in by a shield block check). Multishot for groups (don't max this, just put enough points in to give you a decent cone of arrows in front of you). Freezing Arrow to... freeze enemies in place while you snipe away at them (you can choose to max it and its synergy if you want a source of elemental damage to kill physical immunes, but its main purpose is the freeze). And then passive skills as you see fit.
As a zon, you'll want to acquire an item that grants you knockback asap. This can come from various sources and I think you can even craft some gloves with the knockback mod. Cleglaw's Claw is a good cheap source that also slows enemies by.. 25% I think.
You'll also want some sources of mana leech. Mana leech rings are easy to find, and if you've got an open socket, you can stuff a perfect skull inside to give you some mana/life leech. Don't worry about ruining the item as you can de-socket items now with a hel rune and a scroll of TP.
Multishot does cost a bit of mana, but if you don't put too many points in it, once you start hitting 3 or 4 enemies at a time with a couple of mana leech sources, you'll gain all that mana back.
Sorc:
Orb is good if you want to multispec in another element, as you only need to max orb and cold mastery (don't bother with the the 2% from that weak ice shard spell synergy) for it to be effective.
A popular path to take with frozen orb is meteor+orb or lighting/chain lighting+orb.
Blizzard is far more popular, as it does ridiculous damage thanks in large part to cold mastery. It also has quite the reputation in PvP thanks to the autoaim and TMC people. If you don't have stacks res and/or absorb cold items, you can easily die from one casting of blizzard.