That's how it's done:
Download the free motif template and print it out. Transfer it to the pots using graphite paper. Of course you can also transfer a motif of your choice to the terracotta pot
Use the engraving tool to slowly follow the pre-drawn lines. Once you have drawn all the lines, you can carefully blow away the dust and, if necessary, drive over the lines again
Finally, you can paint the upper edges with colour. How about for example with a gaudy Neon paint? 
