Where do I setup how the driver's commission is computed?

Before printing driver's payroll, you need to first setup driver's payroll settings, under the driver's profile (edit window).  

The settings may be different for each driver. If you pay a driver based on commission, then select the appropriate settings. Then when you settle a trip, LimoWiz will calculate the the driver's commission based on theses settings.

Trip Settlement: 

When a trip is completed by assigned driver, open trip and click the Settle button.
The settle window is where finalize payroll amounts. Driver's payroll calculation is based on what you have in driver's payroll setting as in above image. You may override the amount, then fill in the Settled By field to mark a trip "Settled".
Warning: None settled trips will appear on payroll report but driver's payroll does not include them, i.e. not added to total pay.

Print, Preview Payroll and Verify Trip if They are Settled:

Select Payroll icon on top toolbar 

Payroll Options:

Verify Trips - do this first to see which trips are settled

You may view one driver at time or print a range of drivers’ payroll. Payroll dates are saved for the current period. LimoWiz does not compute the taxes.

You have several payroll report options to choose from, or you can save the report style in the driver’s profile as see in the first figure above.
 

To keep driver pay history on file, edit the driver and click on the Pay History button and add.

It is recommended that you print two payroll sheets, one for office use and one for the driver.

Each driver should have a folder of his own. Check stubs should be stapled as a proof of payment.
 

LimoWiz verifies if trips are settled, i.e. completed. If not settled, driver total for a particular trip will be zero. A trip is settled if Settled By field on trip settle window is NOT empty.

Note: If the trip is settled and you need to make changes, you must edit trip first and the click the Recalculate button on Settled window.

Export Payroll fields:

Open dispatch windows for a range of dates, then right click on any trip to bring the quick print menu.

You export or print fields like TOTALPAY, TIP, TRIPTOTAL, etc.