Expression "to arrive at a place with your hands hanging"
Solution 1:
In A Dictionary of Hiberno-English: The Irish Use of English by Terence Patrick Dolan there is the entry: arm. Here we can read: "He came home with one arm as long as the other (i.e., without any kind of present ...)".
Also, on urbandictionary.com we can read:
One arm as long as the other
Basically turning up somewhere with nothing to give when something is expected. i.e coming to a party empty handed. Irish in origin
Jim: "Dave arrived in late to the wedding yesterday, the clown"
John: "Typical. Did he bring a pressie"
Jim: "Not at all, arrived in with one arm as long as the other [emphasis added]"
So, Spanish expression "llegar con las manos colgando" seems perfectly equivalent to English "one arm as long as the other".
Solution 2:
"Don't show up empty-handed." gets 4,400,000 hits on Google. I'd say that's probably the winner ... hands down.
Solution 3:
My mother has often said that she never liked to arrive at a social gathering with both arms the same length, which I think captures well the spirit of your Spanish expression.
My mother is English, but has lived in Ireland long enough to pick up many Irish expressions. I don't know where this expression originates.
Solution 4:
To have nothing to contribute is, in fact, one of the principal meanings of empty-handed, and what I would turn to naturally: We can't just show up to the baby shower empty-handed!
There are more colorful words for those who exploit others' generosity, though— moocher, freeloader, schnorrer, sponge, free-rider*— or those who would do anything to save a little money—cheapskate, skinflint, tightwad. We can't just show up to the picnic empty-handed, they'll think we're moochers.
Solution 5:
My husband's family, who are Northern Irish, use the expression "the two arms the one length"--which means not carrying anything--to describe someone who arrives at another's home not bringing a gift of some sort, usually to a celebration, meal, etc.