Here's how I make these things. I use Painter 8 and a tablet p.c.
Once I have an idea, I type in the words (I have a typeface that looks like my writing) and roughly sketch them in. Sometimes I draw them separately and paste them in. This lets me fool with the composition.
Then I fade the rough sketch and sketch a tighter layer, with more details.
Note in these early versions that the punchline is different. The original joke was just showing Vespa snapping a picture. The problem was that I couldn't make it clear that this was a camera (and not a Martian ray gun or something). To bad, since just showing her taking the picture would be funnier).
I often force myself to write alternate punchlines anyway. Sometimes it leads to a better joke.
I zoom in for most of the "inking", using painter's Smooth Ink Pen. I'm not satisfied with my inking ability. It's something I need more practice at. Wally Wood I ain't.
Also note that the scorpion actually looks like one this time. His earlier incarnations looked like a lobster Beanie Baby. I was trapped in jury duty when I started the scorpion gags and didn't have web access for a reference.