to create the background use two colors to make a linear gradient using a blue for the sky and a green for the grass. then apply your mask, merge group and duplicate to darken.
using the lawn tube that comes with pspx2 or you can get it from Corel themselves add a new layer and paste the lawn around the bottom of the canvas,don'rt worry about being sloppy we will use the same mask on the lawn layer
to create the cloud use el 26 reduced by 50% free rotate it 90 to the right and apply Gaussian blur at 20, duplicate and change the blend to screen and merge down.
to create the sun use a color yellow and create an preset shape circle the apply a sun corona by eye candy