I've seen people mention putting some sort of "use it or lose it" time limit on the money, so that people are motivate to inject it directly into the economy instead of just sitting on it.
I'm not sure how feasible such a thing is or if it would hurt the cause of keeping the economy moving.
I just don't know how you would enforce this and even if this money "only" helps a family with some means have a cushion to worry a bit less so they can continue as they were it would be productive for markets.
Say you send a prepaid Visa card (this would be terrible because of fees but go with it) to everyone with an expiration date, it'd be easy to parlay that into vehicles that were not "spending" (gift cards, other pre-paid cards, etc) and regulating that is a nightmare.
Once you get into qualifiers and enforcement regimes you're slowing things down and adding percent costs to each dollar provided. I'd say keep it simple.
I'm not sure how feasible such a thing is or if it would hurt the cause of keeping the economy moving.