What's your criteria for choosing an Angel Investor?

One advise I have often heard people talk about is to be cautious of who you are raising money from. One of the criteria I am aware of is whether the angel is going to be reachable when you need help and someone who can help you network and actively help with introductions. There definitely must be more to know about it.

Do you have any experience raising an angel money or accelerator money? What did you look for? And what things did you take care of?

I am not sure if this should be a separate post but I also wanted to ask about any strategies. One I've heard is to start from the bottom of your list so that as you reach the top you are more prepared. And if you read any books to prepare yourself for fundraising.