I have been doodling quite a bit for my sketchnotes, and I wanted to use them to illustrate my Android Summit keynote.
When I organized my thoughts for the talk, I cut paper into small pieces and draw one picture on each. These are the draft illustrations.
Some of them I was not sure how to draw, so I searched on the web for outline images of the concept, and copied it.
Copy pictures from the web
When I first started sketchnoting, I was really hung up on the idea that I was doing art, and copying is a big no no. But I copy code from StackOverflow all the time, and had no problem with that whatsoever. So I started copying drawings, and found that it always comes out as my own style (due to the lack of artistic skills to make precise copies), so I don't feel bad at all about copying.
I pick images that have simple outlines, and not too many curves. I found it difficult to copy curves, and if the drawing depends on the curvature to convey the idea, my copy will look horrendous. So I just avoid those.
Redraw on tablet
Once I was happy with the draft slide deck, I redrew the slides on my tablet.
I did not have time to investigate which software I want to use, so I just did a search on a drawing app on Android that supports layers. I ended up using MediBang Paint.
I wanted layers because I reuse some components of my drawing. For instance, I have a book icon to describe experts as people who wrote books, and then later I have a "Rant Book" where I jot down talk ideas.
It was much harder to draw on the tablet than on paper. The tactile feedback was very different. Also if I rest my hand on the tablet, it will make marks in unexpected places. Frustrated, I wore a glove to prevent accidental touches.
Also, the export UX flow for MediBang Paint was quite clumsy, so I spent quite a lot of time preparing the image files.
Import to Keynote
After I exported all the images as transparent pngs, I imported them into Keynote. I added drop shadows to make them pop on the page. I then add reveals and animations as appropriate.
It was a lot of work to make my own illustrations, especially since I am a developer by trade and did not have a good workflow. But it was totally worth it. I really like the final look-and-feel, which adds a personal touch to my talk.