Here is a picture of a shell I did not too long ago, to go with what Wynney said regarding bubbles.
If you mean water drops, mist some water drops on the shell then spray your colour from a shallow angle from one direction to catch one side of the drops. Then you can either just dry under a hot lamp and back with colour or dry, then use another colour to spray the bubbles from the other side, dry then back.
As mentioned, various videos on the net
|