Since it was close to Valentine's Day I'm showing how to do a heart shape, but this idea will work on any basic shape.
So here is a simple line design I came up with just to get me started. It's lacking the details, but it seems to be a good start. And besides, I have this little voice in my head (that sounds suspiciously like my sister Linda) that says I can put a flower or bow on anything and it will look better.
The dough has been rolled and cut into heart shapes. This shows how you can add detail lines before baking using different cutters or just an off set spatula if the design calls for a straight line. Gently press the cutter just to make a slight mark. (I actually cut these a little deeper than I needed to so they would show up better in the photo) You don't want to cut through the dough completely as this might distort the cookie as it's baking. This way the detail lines will then become baked into the cookie.
Here is a closeup of a baked cookie with the design imprinted.
Another way is to print out the design onto cardstock and cut out the design like puzzle pieces and trace around them directly onto the baked cookie with an edible marker. You don't have to use such a dark color, but I did for the photo.
This technique works well for any design or shape of cookie, and is especially helpful when you have a lot of the same design to do and want all the cookies to look the same.
Sometimes a design vision doesn't look so great in reality. As in this case because every time I look at these they remind me of those sleeper Pj's for little kids with the bumpy things on the bottom of the feet. In hindsight I think I should have done a wet on wet technique for the polka dots.
For these cookie the background was flooded first and allowed to dry before flooding and sugaring the ribbon accent. After the ribbon area dried I added the dots and bows. I made the fondant bows ahead of time using a flexible mold.
A simplified variation still using the same colors but without the sanding sugar and polka dots. I also added different icing details.
Here is another set of heart cookies with the same basic design from the line drawing, but a different color scheme.
I iced the ribbon area first this time and let dry, then flooded and sugared the background.
The royal icing bows, drops and flowers were made ahead of time and added after the sanding sugar was dry.