Safety
There are quite a few safety considerations when going off-piste. In the US the ski patrol will “secure” all the accessible areas of the mountain, both piste & off-piste. In Europe only the pistes will be protected, there have been several bad accidents literally 100 metres from the edge of a piste. Probably the biggest danger is avalanche, with a frightening number of deaths every year. We control our risk both actively & passively – active control is avoiding the dangerous slopes by assessing conditions (see below), passive control is by carrying equipment like transceivers, shovels & probes.
Other safety aspects are crevasses (on glaciated areas), under snow hazards (trees, rocks, frozen water, holes), cliffs or other steep drops.

Snow Conditions
Getting the snow conditions right is paramount to both safety & fun. No-one wants to be skiing in breakable crust whilst on another slope just a few hundred metres away there is good powder snow available. Factors that dictate snow conditions are – date of last snow fall, wind conditions, sun, temperature, altitude, time of day & aspect. You can get great information on a variety of websites such as pistehors; by checking the local weather forecast and by chatting to local guides or ski patrollers. On that subject – in France the ski patrollers will be more than happy to give you advice on off-piste conditions, they are not there to stop you ducking under the barriers – they are there to help you keep safe.
Every resort will publish an avalanche risk index each day. If the risk is 3/4 be very, very sure that you are going onto safe slopes. If the risk is 5 then probably there are no safe slopes to be skied, stick to the piste or stay in bed.