QICPIC: How should I determine the most suitable filter conditions for the user result of my application?

Use the particle gallery for visual control, if your selected set of filter conditions is suitable for your application. The procedure is as follows:

Select a measurement
Open the particle gallery's dialog.
Define a set of filter conditions
Apply the set of filter conditions to the selected measurement.
Inspect the particles being found by the software.
Name and save the set of filter conditions, if the particles fulfil the expectations or modify the set and go on with Step 4 otherwise.