It's very easy to get lost in the wilderness without landmarks. Hiking trail waymarking serves to make navigation easier. However, it doesn't do everything on its own — you also need to know how to interpret it and how to distinguish hiking trail waymarking from mountain biking waymarking, hunting markers, equestrian trail signs, and so on. Here's what you need to know about hiking trail waymarking to have all the tools necessary to stay on course.

The different types of waymarking
In towns and cities, various markings help us understand the highway code on different streets and intersections — traffic wardens, traffic lights, road signs, road markings, and so on. In hiking, it's much the same thing.
For instance, there are signs that provide hikers with all the information about their route. Hiking signs are generally found at the start of a trail. They typically display information such as altitude, key landmarks, estimated walking time, the type of waymarking used, and so on. Once you're on the route, you'll encounter signs indicating your current position and the direction to follow to reach the end of the trail.

Markings
There are also painted markings, which can appear on a variety of surfaces: walls, rocks, trees, posts. Speaking of posts — they are generally used on sections of trail where it's not possible to place or spot ground markings, where there are no trees or walls, and especially where there is no defined path. The priority when waymarking is to paint indications on non-movable elements (walls, rocks, trees…). Posts are used when nothing else is available — but they're practical when you're hiking in snowy terrain, as they're rarely buried under the snow.
There are also cairns: small stacks of stones that hikers build on hilltops to serve as landmarks and indicate the way forward. Many other types of markers exist too — and learning to correctly interpret each one is key.
Interpreting hiking trail waymarking in France
Hiking trail waymarking is a system of signs and landmarks to help hikers stay on track. There are hundreds of systems worldwide, but we'll focus on the one used in France. French hikers are fortunate to have the Fédération Française de Randonnée Pédestre, where volunteer waymarkers maintain the various markers. You can distinguish between GR markers (grande randonnée — long-distance trails), GRdP markers (grande randonnée de pays — regional long-distance trails), and PR markers (petite randonnée — short-distance trails). Each type is identified by its colours. Long-distance GR trails are marked in white and red. GRdP markers feature two colours: yellow and red. Short-distance PR markers are in yellow.

The different waymarks
You'll find various types of waymarks — GR, GRdP, and PR. The most important thing is knowing how to read them. On GR and GRdP trails, you're on the right path when you see two horizontal stripes stacked on top of each other (the colour depending on whether it's a GR or GRdP route). On a PR trail, you'll recognise the same marker as a single horizontal yellow stripe.
These indications are supplemented by an arrow when you need to change direction. You'll also find indications when you're not on the right path. For GR trails, you'll see a red and white cross. For GRdP trails, the cross will be in yellow and red. For PR trails, a yellow cross tells you you're heading in the wrong direction. Overall, waymarking in hiking is common-sense based and easy to understand. Once you're used to it, reading the markers becomes second nature.
When in doubt, look a little further along the supposed trail for the next waymark to confirm or rule out your choice. Generally, within a few dozen metres — sometimes less — you'll find a cross indicating the path is wrong.

Stay on course!
It's easy to get lost while hiking if you don't have the right reflexes. First and foremost, learn to use the waymarks continuously — they're there to help you navigate, so the least you can do is follow them. That said, markers don't do everything in hiking. It's important to know how to navigate usinga map, and to know how to use other tools such as a compass or a GPS. These tools will tell you where you are and where you need to go. Another tip to avoid getting lost while hiking is to track your progress on a map.
Use your GPS to determine your position, or mark your location as you go. Then note that point on your map, specifying the time at which you passed it. Since you have an estimated journey time from the start of the hike, this should give you a rough idea of how much trail remains. If you've been walking non-stop for two hours when the map suggested you should have arrived 45 minutes ago, it's time to check your bearings.