First I created a storyboard with 16 panels, each the size of the animation (320 x 240), in a 4 by 4 grid:

I put this vector layer in a group layer, together with an empty vector layer (for drawing on the storyboard). In frame zero, I shrank the group layer and translated it, so the complete storyboard would fit into the visible field. In frame 1, the storyboard got the normal size and position.
The next step was to move the storyboard in the timeline, so that an animatic would be possible. I used camera tracking to do this. During 96 frames, the camera shot panels 1 through 16.
Now I could draw with the frame counter at the correct position in the visible field and in the correct panel. The only thing I had to do was: go back to frame zero, copy the relevant keys from the frame I just worked in, paste them in frame zero, and then delete them. Working through the panels, by working in the appropriate frames in the timeline, and copying the keys back to frame zero, I finished all 16 panels.

This was just a simple example (numbering 1 .. 16). The resulting movie looks like this:

Here is the file animatic.moho.
I can think of some refinements:
- use an arbitrary size for the panels, so it's possible to track or zoom the camera when the panel is visible in the timeline
- use a couple of frames for simple animation (e.g. translation of the character in the panel)
- use the timeline to determine the length of each scene
So basically, you create a panel on the panel layer, which give you the bounderies to draw in the drawing layer. Next you track the camera to the panel at the appropriate frames within the timeline.
I think this way you can quickly create a storyboard and animatic, to see if things work visually as you had envisioned it from the script. You can leave things out, by not tracking to a panel and insert things by adding a panel and tracking to it with the camera at the appropriate frames in the timeline.