I DE them unless I can see a value in them (i.e. if I would use that item myself on any character).
And if it doesnt sell 1st time I just shard it also.
You could try your luck on /trade. Or at least advertise that you have it on AH.
Some people look for gear, but their value is generally random.
I found myself having the best progress in terms of time and gold when I made sure to run a minimalist bag: use (soon) or vendor. The time I took organising, mailing around, extra laps due to fewer free bag space, didn’t usually offset what I could earn anyway in that time.
I don’t know enchanting prices on your server but between AH cut, deposit (a few times), I didn’t see much profitability of keeping items for enchanting. Auctionator gives a fair estimate on DE value, might want to fiddle if it’s 2-3 times the vendor price at least.
Whether people buy those for use depends on server (and account) maturity, I didn’t ever spend money on a level 20 blue, just because. And most of those I try to sell return, too.
For low levels, you should always consider how much gold you’d earn at level 60 during the same time window. (Forgoing petty profit taking minutes to realise enables you to level faster.)