I have never been lost, but I will admit to being confused for several weeks.
Tell someone where you are going, the trails you are hiking, when you will return and your emergency plans.
Your hike begins before you reach the trailhead. It's important that you research, write down and distribute your plan before you leave. Include:
Discuss the plan and leave a copy of the plan with someone who is reliable and responsible, and who knows how, when and why to contact authorities.
If your plan changes, call this person! You don't want a search and rescue team sent for you if not needed.