This method will make the field label red if the field is left blank, therefore drawing attention to the field. This example uses the Company field; however, this can be done for any field in the top-half of the screen or the Fields tab.
Right-Click > Properties on the Company field while logged in as a user with 'Master' rights. Then go to the Color tab.
Click on the Expression radio box under Label Color and enter this:
iif(trim(company) < ' ', 255, -1)
If you are using a different field you'll need to substitute that field name for 'company'. The 255 is the color red while the -1 is the default label color.
Now when the field is empty, the label is red; when data is entered, it changes back to the default color.