Many of us have been moved to help victims of the two recent earthquakes in Mexico, or the people living in Texas, Florida or Puerto Rico, whose homes have been destroyed by hurricanes.

While you may hear of donation drives for food, clothing or tools, GlobalGiving Chief Program Officer Britt Lake says giving money is often best in situations like these.

“You know, I can’t tell you how many times I’ve been in post-disaster situations where there are piles of things given with the best of intentions, but aren’t especially useful in the context that people in the community need,” said Lake.

She added that giving cash allows charitable organizations to purchase the things they actually need when they need them, and “often to get them in bulk or at cost in a way you as an individual can’t get the best bang for your buck.”

With that said, not all organizations are created equally, and smart donors will do their research. GlobalGiving, which is raising a $2.5 million Mexico earthquake relief fund, vets partner organizations before doling out donated cash.

If you’re looking to donate to charities directly, search the organization name on sites like Charity Navigator or GuideStar, which rate organizations based on their use of capital, transparency and accountability. GlobalGiving has received a four-star rating from Charity Navigator and a platinum-level rating from GuideStar.