well there are lots of ways really.
i use an ancient version(8) of corel paint usually .
draw a white circle on a black background
draw a little triangle (or any other shape tooth) and copy and paste it round the circle)
if i use corel draw(8) it makes it a lot easier because it remembers the last movement and rotation using duplicate.
another way is to get a photograph or drawing of the internet and convert it to black and white.(but remember curvy needs 24 bit rgb for inflate so you will need to convert drawing back to 24rgb)
serif drawplus (and i am sure many other paint programs have a polygon tool to draw a star with as many points as you wish)
many cad drawing programs are designed to draw gears easily.
the higher the resolution of your drawing the more accurate it will be in curvy
(but the longer it will take to inflate and will use more memory)
here is a link to one method
if you google drawing gears
i am sure there will be plenty more ways
here is one drawn with serif photoplus adjustable selection tool
(about 20 seconds)
inflated with curvy(about 15 seconds)