You can get 3-D paints at craft stores. If you are painting a t-shirt, canvas shoes, jean jacket, hat, etc, you can get some cool effects with 3-D paints.
You can do the whole design with 3-D paint, or just do outlines. You can add rhinestones or color beads (they look great as the centers for flowers). Pastel and regular colors work best on white or light color fabric. Neon colors can also be used on black or dark fabric.
Allow 3-D paint to dry – usually overnight – in a safe place.