Whether it's your first or fourth time, or you've been skiing regularly for years (35 in my case), there are a number of basic decisions - where and when to go - self-catering, hotel, or catered chalet - package or DIY - how and when to travel - where to find what you want. These factors are inter-dependent and are determined by the style of holiday you are looking for.
In the Alps, ski lifts typically run from about December 20th to April 20th. This involves employment and other contracts so lifts are unlikely to open in November or May, even if there is a lot of snow. There are just a few resorts usually those with glacier skiing such as Chamonix, which have a longer season.
All of February has French school holidays and tends to be solidly booked. Avoid it if you can. The middle two weeks are the most popular, crowded and expensive because other countries have their holidays too. Many people have no other choice because they have children or are otherwise involved with schools. All considered, we regard the last two weeks of January and first two weeks of March as the very best times.
If you want to ski at February half-term, book six to twelve months ahead - especially if you are a family of more than four people.
Christmas, New Year or Easter are also great times for a winter holiday, but it is not just about the skiing. It is a good idea to go for the ambiance of a family resort and to avoid the famous international resorts where restaurant prices can be steeper than the pistes.
The low season weeks - early January and late March into April - are much cheaper and never fully booked, so these are the times to take advantage of cheap flights or last minute package holidays to grab that extra week.
Purpose built, high altitude resorts are favoured by the English who are worried about lack of snow. These resorts have good snow reports for a few weeks more, which suits the tour operators. Being developed purely for tourists, they have large hotels complexes and are well marketed. In many, the majority of clients are English. It's the easy option for a package holiday, or last minute bargain - but you do tend to be locked in to one place with whatever skiing, restaurants and entertainments it provides.
Low altitude resorts are generally more attractive, more relaxed and more reasonably priced. There is less risk of piste closures due to high winds, avalanche or severe cold; and usually there are trees to preserve the pistes from sun and wind. Lower resorts generally get less snow but they need less snow because the pistes are not based on bare rocks or sharp stones. For example 20cms of snow at Combloux is as effective as a meter at some high level resorts and the snow holds better because the pistes are below the tree line.
For most of the ski season, good conditions are equally likely at most resorts. Only for the first 10 days and last 4 weeks of the season are conditions sufficiently better at high altitude to overcome the drawbacks (and then only if you are desperate to maximise skiing because the pistes may have been overused and become very icy). If the skiing is not good, it is more pleasant to stay in a real village with a choice of other interests. In Combloux, you can still get around even if 50% of lifts are closed and it is always possible to drive to several other resorts.
When chosing a destination, an important factor is what style of holiday you want. For example, Chamonix is a town with lots of street life and international skiers but don't expect to find nice little mountain huts for lunch and drinks on the pistes. Megeve has rather more sophisticated and subdued nightlife but does have several mountain restaurants. Places like Flaine and les Menuires, have good skiing but no mountain restaurants apart from the lift stations and people are obliged to eat out in the evenings or stay cooped up in a large hotel/apartment complex. Villages like Combloux have very pleasant and attractive stops for drinks and lunch and the mainly French clients spend most evenings in their apartments or take the children with them to the restaurant. Thus nightlife is very quiet but pleasant and reasonable priced - especially at festive times like Christmas, New Year and Easter.