Before giving directions, establish the starting point: "Are you standing outside the main entrance or inside the station?" A perfectly clear route from the wrong entrance will still send someone the wrong way.
Use a route you know and choose visible landmarks. For example: "Leave through the main doors. Turn right and walk past the pharmacy. The cafe is on your left, opposite the bank." Keep the sequence short enough to remember.
Separate position from movement
Compare "The cafe is on the left" with "Turn left at the cafe." The first locates something; the second tells the listener to change direction. Practice both with a simple sketch so their different purposes are clear.
Add a useful boundary: "If you reach the bridge, you have gone too far." Only use a landmark that actually exists on your practice route. For an unfamiliar real location, checking a map is more responsible than confidently improvising directions.
Ask the listener to repeat the critical turn: "Which way will you go after the pharmacy?" If they misunderstand, simplify that section. Avoid a vague "You cannot miss it," which supplies no new information. Finish by naming the destination again and, if relevant, its entrance. A route can reach the correct building while leaving someone at the wrong door.