I like to start with a discussion, rather than a presentation and Q&A. For me, I find that really understanding the problem is the hard part. Once I really know what I need, what my requirements are, the options fall into place.

Today, for example, I'm going to have a whiteboarding session with one of my employees. We're going to whiteboard the problem we're solving, again, and again, until we both can describe high and low level details in our sleep.

Then we'll do a few searches and leverage other people's experiences to pick our technologies.

The also works for pure architectural discussions. You have a queue between your web server and web workers -- why? etc.