A good star mask is essential for good results. Though the Shrink module is much more gentle on structural detail than the basic unsophisticated morphological transformations (such as minimum filters) found in other software, ideally, only stars are treated and not any nebulosity, gaseous filaments or other structural detail.
The 'AutoMask' button launches a pop-up with access to two quick ways of creating a star mask. This same popup is shown upon first launch of the module. The generated masks tend to catch all major stars with very few false positives. If you also wish to include fainter, small stars in the mask, then more sophisticated techniques are recommended to avoid including other detail.
Besides touching up the mask by hand, it is also possible to combine the results of an aggressive auto-generated star mask (catching all faint stars), with a less aggressive auto-generated star mask (catching fewer faint stars, but also leaving structural detail alone);
StarTools stores the masks you used in your workflow in the StarTools.log file itself.
The Heal module was created to provide a means of substituting unwanted pixels in an neutral way.
The Color module is very powerful - offering capabilities surpassing most other software - yet it is simple to use.
Preset buttons can be distinguished by their icons; they bear the icon of the module you launched.
You can convert everything you see to a format you find convenient. Give it a try!