Removing your mask (or stencil) before the paint is fully dry is a great tip. When using spray paint, letting a fine mist of one color fall onto a field of another not-quite-dry color can lead to some fun results.
Here’s Bob with a speckled blue background:
And this red/black mist on an orange background:
Of course, spray paint comes in a range of flavors. Cheap- and mid-range spraypaint (like store brands, rustoleum, or krylon) are generally going to be enamels, and are pretty low in pigment content (the actual little bits of color mixed in with the propellant and solvents). Stepping up to “fine-art” spray paint will give you a much higher pigment-content, and options like low-pressure & variable pressure caps, acrylic spray, oil-based spray, water-based spray, chalk spray, phosphor, and much more. You will also get better adhesion, quicker dry times, and less drips. My personal favorites are from MTN and Molotow.