The essence of the Kawaii term is cuteness, charming images and style, with small baby like proportions, soft, simple and cartoonish.
The secret is in the palette you choose, and soft colors are more appealing in this case. the rule is bright pastels in rainbow like spectrum. They give a sweet and soft ambience.
Keep your artwork simple, outline your images, refine your line art, avoid sharp edges, the keyword here is rounded, imagine you are drawing a squishie, it helps. Maintain a simple color scheme, no more than five colors. Use cell shading adding soft gradients. And one light source.
Most important is to consider, that your image most have a personality, that is why almost everything in the Kawaii world has a face, a cute one, sometimes funny, with wide eyes, a small nose and mouth.
Bubbles and Bubbles 