You can teach workshops. Honest. Anyone can. It's rewarding and if you play your cards right, it's fun. The most fun I've had at a conference is doing a workshop.
Everyone knows something. You have specialized knowledge - whether it's about a time in history, a specific location, a method for getting into character, or for writing 40,000 words in two days. Try brainstorming a list of things you know. Identify one or two you'd like to work up into a presentation. Brainstorm out all of the things you'd want to tell fellow writers about on your chosen subject. Now decide whether you want to talk for forty-five to fifty minutes while people take notes, or whether you want some participation in the form of writing exercises or even getting people on their feet to try what you're talking about. Does your subject matter allow for the use of media like movie clips, slides or other audio/visual?
Know thyself, workshop presenter. Can you speak from a simple outline? Or do you need your presentation fully scripted out?
From your brainstormed list, build your outline and/or write up your presentation. This is a rough draft. If you have to do some research to fill in details or history, that happens now and fills in your draft. Let it sit for a week. Go back to it. Rearrange as the mood moves you. Tighten it up. Fill in details you'd forgotten until now. If you have photos or clips that you want to use in the presentation, build that file and note in your presentation outline which photos or clips go where. You can build the whole thing as a Powerpoint presentation if you like that sort of thing and if it won't divert you from writing your own books.
Set up your presentation and try speaking all the words - give the workshop to your stuffed animals or your action figures. Time yourself. Is it physically possible to say everything within 50 minutes? Breathing is not optional. If you don't breathe, neither will your audience. If you aren't comfortable saying what you have to say within the time constraint, no one else will be either. Speaking too quickly means no one absorbs what you say. So speak slowly and deliberately. Make heartless cuts to your content in order to fit comfortably within the time allotted.
Now, you need guinea pigs. Ask your local writer's group if they'd let you do your workshop for them. Most groups will. Ask for feedback and really listen to it so you can learn from it. You're not looking for public speaking critiques - at this point, you're vetting content. Did people feel like you left out anything vital? Where they overwhelmed? Would your audience have liked a copy of your notes? A list of your source materials so they could do some further research? Consider adding those things.
See if there's another writers' group in the next town/county/whatever that would let you do the workshop again. You're doing it again not only to work in feedback, but also to become more confident with your material.
At this point, you're ready to propose the workshop for a conference. Most conferences only allow 50 minutes for workshops (to allow people to get from place to another on time). If you intend to answer questions, plan for a few minutes.
At a conference, you'll want to state a few ground rules right up front.
1. Most conferences have people pitching - say so and tell people that if they get up and leave, you'll assume they have a pitch and you don't mind (and then don't mind or take it personally when someone leaves)
2. Point out the restrooms
3. State whether you'll take questions as you go, or whether you prefer that people hold their questions until the end
Then dive right in. Have fun. Invite your audience to have fun. If you screw up, laugh at yourself. No one gets shot at dawn because you lost your place.
Save your notes! After you've done your workshop, you have the groundwork for an article on your subject.