When things have to go quickly
Basic vocabulary or not, in every situation where you are making sketchnotes, you will come to a point where you want to draw a symbol that you cannot do quickly. In this case, just leave enough space and quickly write in pencil the word you would like to visualize. The completion will then come later, when the presentation is over.
The failed Maya the Bee and the finland telegram screening subsequently drawn Pumuckel
In this sketchnote from the InspiCon 2018 in Bonn, I tried to draw Maya the Bee that Mike Krüger mentioned during his talk and realized that my inner image of the bee from the cartoon series was not as solid as I thought. I didn't even try to draw Pumuckel and just wrote "Pumuckel" briefly. Then, in the evening at the hotel, I used Google Image Search and drew Pumuckel. You see, cheating is allowed!
What else can you do if you want to create sketchnotes really quickly?
Work only with filler or marker, colors and shadows follow later
If you want to work with colors, work only with a single
Use fine pencil lines (hardness F) and reserve space for your graphics.