Tutorial 7: How to tickle your effects
(You may like to print this tutorial (see under the File menu of this window), it is about 1 A4 page long.)
You will learn in this tutorial how to randomly modify the effect settings, but without changing the effect.
Step 1) Bring in the photograph, choose the stardust effect:
Step 2) Now click a few times on the Sample buttons until you find an image you quite like. Then either "Fine tune" it or click on "Apply Filter".
Step 3) Once you have made your first image click on the tickle
icon 
and a new version of
that image with your selected effect will be made.
The tickle icon is a bit like the sample buttons in the effect selection dialog (shown above) , but it works on the full sized image.
The tickle icon will not change your mixing settings.