To edit tracks I use Garmin basecamp.

The downloadable file includes the track to follow and the waypoints:

• Drinking fountain. Label: water; e.g. water 1; the number refers to my database.
• Danger. Label: DANGER; usually it shows a point of dangerous uneven road.
• Single ramp. Label: percentage value+grad; e.g. 10% grad = single ramp with 10% slope.
• Starting point of a climb. Label: UP+lenght of the climb+percentage average slope+av+percentage maximum slope+max; e.g. UP 6,3 km 7,2% av 13% max = climb with length 6,3 km, 7,2% average slope and 13% maximum slope;
• Highest point. Label GPM+name of the place; e.g. GPM Montemonaco.

Let me remind you that a gpx track can’t  replace the common sense and the caution that should always be with us on the road. Danger is always around the bend and sometimes is unforeseeable, even because of wether conditions. Tracks and waypoints just help you if you don’t know the way, nothing more.