Use the straightedge of your plotter to mark your course line on the chart with a pencil. Simply connect your starting and destination points. Take care that you do not cross through restricted airspace. If you are flying from navigational aid to navigational aid, you may require several legs (or lines) on your journey. Mark as many legs as are required.
Use the scale on the plotter -- making sure you are using the scale that matches the one used on the chart -- to determine the length of your course, measuring each leg individually.
Measure the true course for each leg of your course. Do this by placing the small hole in the plotter's center over one of the chart's longitude lines. Align the straightedge of the plotter along the drawn course line. Read your true course where the longitude line intersects the plotter's azimuth, which is on the protractor portion of your plotter.
Determine the effects of wind on your aircraft's direction. For this, you must get the winds-aloft forecast. Use your flight computer to solve this. Plug in the values for your true course, wind direction and wind speed to get your true heading.
Add or subtract variations to convert true course and true heading into magnetic course and magnetic heading. Find the magnetic variation printed on your aeronautical chart. Adjust according to the memory aid "East is least, West is best." So, if your variation is marked as east, then subtract the variation from your true values to derive magnetic values. If the variation is west, then add the variation.
Your course is now plotted. This portion of planning your cross-country flight is finished.