Google Earth or UgCS. I use Google Earth to plan my waypoint missions then I can look at it horizontally to make sure I am clearing everything in my flight path. Then I import it to Litchi and off we go. Keep in mind that Google Earth is using images that can be very outdated. I noticed that in my area, they are only a couple months old, but in other areas I have seen stuff older than a year. After I import into Litchi, I always add a buffer zone to be sure I am going to clear everything. The best thing about Google Earth is you can fly relative to ground elevation as opposed to your take off point.