I love using split cakes, for me they are a game changers. Even simple design can look awesome with them. This is my "go to" design when kids don't know what they want, I let them choose their favorite split cake and let the magic begin.
Load your petal sponge with favorite split cake and create mask around eyes, watching that brightest color is inside/in center and darker on the outside framing our mask. Wipe of any extra paint and make sure that mask is symmetrical.
Here you can get creative and paint what ever you want; roses, emojis, stars, or leave it without (see image below without roses for a simple version). This time I went with blue roses to create some contrast.
We are gonna "close" mask with set of teardrops using DFX white and round brush No 4. Most important thing is to master your lines and swirls so they look bright and crisp. Loading brush properly is important to, spray your paint with water and then with brush activate white to a creamy consistency.
When painting mask design, pay attention that both sides are symmetrical. That doesn't mean they have to be exactly the same but they should have same flow. Add some dots and we are done!
If you want even more simple design here is example:
Those are my favorite split cakes from Silly farm;
Silly Farm Split Cake Juicy Fruit