Training on-site at customer locations is sometimes challenging. Every classroom is set up differently, and that means having to be adaptable to the tools available.
For example, I like to draw on whiteboards as I talk, but many classrooms have such a big pull-down screen that the whiteboard is almost completely covered. It's a hassle (and distracting) to constantly raise and lower the screen.
My accomodation to this was to open a Word document, set the font to 24 pt. Arial, and use it to type my notes. It was awkward at first, but after a while, I found I really liked this approach. I can use the notes during review on future days without messing with bulky easel pads. And I email the entire whiteboard document to the participants after class is over, which makes a good "after sale" reminder of the value I've delivered.
I'm still struggling with how to draw diagrams: the tools in Word are a bit primitive.
One tip: back up the whiteboard to a flash drive before you leave each day. Some classroom environments reset themselves upon logout, and your documents might not be there the next day. Also, some on-site training rooms are shared spaces that others might use between class sessions. Be prepared: backup!