Providing you behave responsibly and avoid putting yourself in danger by taking too many risks, skiing and boarding are relatively safe sports - leading to fewer injuries per head than such run-of-the-mill sports as keep-fit, tennis, squash, cricket and rugby. So, as long as you are sensible you should be confident in the knowledge that you are not putting yourself unduly at risk.
Preparing for the slopes
On-piste you should be safe from most of the natural dangers of the mountain. Your biggest risks are falling on ice or colliding with a tree or with another skier or boarder due to your own or their incompetence or recklessness - so make sure you watch and keep a safe distance from the people in front (downhill) of you. Here are a few points to remember when skiing or snowboarding on the piste:
Abide by the Code of Conduct
When on-piste make sure to follow the rules of the 'Skier's Highway Code.'
Stay within the piste markers
Remember to stay within the bounds of the piste - marked with sticks or posts. (How well they are marked - which matters during a white-out - varies a lot between resorts, but in principle there is a clear definition of where it is safe to ski and board.)
Choose the right route and pistes
Read your piste map carefully to avoid venturing into territory that is beyond your capability or you could be getting yourself into sticky situations. The runs are graded for difficulty so you should be able to work out what you are capable of doing. Green runs are the easiest, followed by blue, red and then black. Remember though, grading can be very inconsistent between resorts - some Val d'Isère greens would be graded red in many other resorts, for example - so if you are a novice, treat unfamiliar runs with some caution. Piste maps are available at most gondolas or main chairlifts, or in many ski hire shops or tourist offices.
Don't go on closed pistes
Pistes are checked against avalanche danger; if there is a danger, they are kept closed until the avalanche has been artificially triggered, or the snow has stabilised naturally. They can also be closed due to lack of snow, which might uncover rocky patches. So don't venture under the barriers of a closed piste - you will be putting yourself and perhaps others at risk.
In general, pistes are patrolled so that injured skiers and boarders will be found - especially at the end of the day when the runs are checked after they have been closed. (Patrolling should also mean that obstacles such as rocks and bare earth are marked.) If you are injured, wait calmly for help.