The following is hypothetical. (But not hyperbolic .)
So, everyone has interests. People with Asperger's have intense interests, but not always interests that other people share. If you share them with someone else who also shares that interest, then you have something to talk about with that other person and, importantly, a /behavior/ about which you can be passionate. Moreover, since some degree of passion is required for friendship, you have something of value that a friendship can be built upon.
But what are you supposed to do when people don't share your interests, but you still need friends? A situation where this would be necessary might be found at work, at church, or, especially, at school. Maybe you can identify other peoples' interests and if you share them, share your passion in their interests with them, and if you don't share them, at least passionately relate them to your own interests to their interests (but within reason).
There would be a lot of work involved in this. First, you would have to compile a list of questions to ask people to know what their interests are, and second, you would have to spend time researching other people's interests to know what to say. The key would not to be passionate about the interest, but just about sharing what you know with the other person and relating it to what they know.
This sort of strategy obviously not help with facial expressions or body language, but maybe it still can be helpful. Or not. It's just hypothetical.