This is known as a S.N.A.M. Serious non adjustable mistake if you do not have the basic skills to start with. There are so many ways to sort this out. Rule no 1. Never tell the clients that you are temporarily unsure of your position. Keep asking them where they think they are as an exercise, this will have them involved and make sure that you are keeping a watch on where you are. An added benefit is that if something happens to you they will have a better chance to get you all out of there.
The best way not to get lost is to keep checking your route and position continuously. Look back regularly so that you have an idea of what to look for when returning along the same route. Following your own tracks is another way to return along the route.
You do not have to make a scene of navigating. Watch your shadow as you walk and make 15 degree adjustments per hour. Watch the surrounding terrain. Hills and valleys, when taken into consideration are a great way to formulate a route in or out.
Awe is a common feeling to most people who witness another person using the stars to navigate. There is nothing magical about looking up at the stars and being able to decipher the pictures and thence use them to find the cardinal points. Once you have found North you can determine virtually other direction and then make an educated guess as to where you have to go.
The orientation and navigation course that Ecotraining presents for the one year course gives 33 different ways to orientate yourself. Why so many? Well, you might not be able to see the Southern Cross due to cloud cover in the Southern sky. Just turn around and use another constellation to the North. Orion, Leo, Pegasus, Carina, and Gemini can all be used as a single indicator or in conjunction with others to confirm your readings.
Think about this and practice all your skills on a regular basis. Scaring clients is not part of guiding.