Buy vanguard or crucible armor and break them down. Don't get helmets though, they're more expensive and provide the same amount of shards.

Do legendary items work the same way the blues and greens work, where if it has been upgraded at all it gives more materials? I've been using the bounty experience rewards on my greens and blues, level them up until i would have to spend something other than glimmer on them, then dismantling them for a bigger reward. Would that work for legendaries or no?

For shards, I honestly think the raid is your best bet. I got nothing BUT shards from it. (#thestruggle) You could also buy legendary armor from a vendor and dismantle it for some.

alts are the fastest way. it's how the first level 30 got there so fast.

alts? and yeah i need to find people to do the raid on normal with. Im a lvl 27 hunter on xbox 360