Open a new document with the default frame rate (12fps) and size
Now select the brush or pencil tool of your choice (I will be using the brush tool as it is fairly simple)
Draw
a shape for the example I will be drawing a heart. The same thing could
be done by using different shapes. You can not write in text when doing
a tween.
Now go to time line 20 and insert a new key frame it should now look something like this.
Now click on timeline 20 and delete the current picture on there so you get a blank canvas.
On
the blank canvas now draw any other shape or writing for example I will
write 'Maria' (remember you can not use the text tool for tweens).
Now
go to timeline 1 press shift, and hold it down, and click on timeline 20
this will select the 20 frames for you. Now right click in the
frames and select 'Create Motion Tween'
In the properties bar you will see where it says tween, open the drop menu and select shape
You are done now, press enter... and watch your tween get played.