For on-trail hiking, this is the single most important navigation skill. Use dead-reckoning to predict your ETA at future landmarks and to approximate your current location.

Backcountry navigation is an art. The basics can be learned quickly, like dead reckoning, reading a map, and using an altimeter watch. But extensive practice is necessary to seamlessly and flawlessly apply these skills in the field, especially when under duress or in challenging situations, like off-trail in a heavily forested area with rolling hills.