I put together a Pinterest board to give you some ideas! You can click on the link to the left.
If you paint black glaze on the letters (for instance if your mug says "dad", glaze black into the indented letter,) let it dry and wipe off the extra, your letters will show up better. You can glaze the tile on top a different color.
You can put some glaze on a plate, dip your finger in, and add fingerprints. You could make a fingerprint heart, flower, rainbow, or just fingerprints all over!
You can carefully glaze flowers all over or one big flower in the middle.
If you want a softer palette, you can add water to the glaze and use them like watercolor paint.
You can add words! Paint your mug all one color or many colors and then use black to glaze words on top.
Your glaze colors can be mixed, so if you want a lighter palette, add white. Just remember complementary colors get muddy and brown quickly, so be careful! There is a color wheel above to remind you how to make secondary colors.