Presidential Possibilities

What qualities do we think of when considering who was, or might be, a capable president? The most obvious would be "makes good decisions", but how does one know that ahead of time, especially when we can't know what the issues will be? Even a good or poor past record says little about the future. After all, no president can be an expert on everything, and advisers can be wrong, too.
There's also the matter of how we view a president as a person. Should he be like Reagan, never too far from seeing the office as a role? Or is it just as good to be like Coolidge, who was willing to make decisions, but not to talk about them?
I saw Senator Elizabeth Warren on TV not long ago discussing several things. This is a person who came from humble circumstances in Oklahoma, becoming a Harvard professor. She has now done what many presidential wannabes have done in the past - written a book that emphasizes her own history. In the interviews I saw, she seemed a little like Margaret Thatcher - decisive, with some impressive accomplishments to boot. And by "impressive", I mean "forced the financial overlords to make refunds to people like you and me that totaled in the billions". That's something not many can say, especially since there are plenty working the other side of matters such as this.
Ms. Warren isn't young. She turns 65 next month, and you wouldn't call her "glamorous" even though she gives the impression of being a good listener who has taken care of herself over the years. She says she is not a candidate for president (she's a Democrat) and might not change her mind. But she knows, I think, her way around the political minefield as well as anyone. I liked a little homily I heard her state so much that it's now on our family bulletin board (the frig): "You can't get what you don't fight for." Well said, Madam.