My wife and I are quite careful about what causes we donate to.
Our local charity is operated entirely by volunteers, except the manager, and she is paid by the city, so we frequently donate food there. Our church has a welfare organization that is operated very efficiently, with a lot of donated labor, and 100% of donations are used to help people. What St. Jude's does is wonderful, and so we will donate to them from time to time. It is one of the very few national organizations that I donate to. Most of what I donate, including my time, is directly to local charity organizations.
While Red Cross may do good work, way too little of donations goes to help people. Same with Salvation Army. But few of them chap me off as much as those that claim to support local law enforcement, but very little makes it there. Some time ago, I was contacted for a "fundraiser" to buy ballistic vests for police dogs, and donated to it. They led me to believe that this was a local fundraiser. Later, I talked to a friend who was on the local PD, and asked him about it. He laughed at me, and told me that the PD got nothing. Never again.