How long are you going for?
A weekend
Only have 2 days to get away? Do the tour of the resorts near you. OK, if you’re in the Paris area then that could still be far away, however if you can go by train then you’ll beat the fatigue. Ideally, plan on leaving Friday evening to avoid losing half a day on the slopes. Go for a smaller resort so you don't waste time choosing the slope for you among the resort’s 170 downhill options! You will also discover the whole area in 2 days and feel like you have really made the most of it.
One week to a fortnight
Have time to enjoy yourselves? Choose a resort with a choice of slopes to work your snowplough. Ideally, one that is connected to other ski areas for the days when you want a change of scenery!
You plan on coming back every year because you like to create rituals
In the same vein, if you're counting on just one resort for your next 10 years of snow weekends then choose something pretty big so you don't go round in circles every year!