When deciding how to get to Laax from the airport, choose the most comfortable option. The closest way is from the Ilanz or Lyon train station. The journey will take about 2.5 hours. From here, the highway to Laax is 4km and Flims is 7km.
You can take the train to Chur (just over 2 hours from Zurich), from here to Laax is 33 km of good highway. Everyone who has been there recommends this road as scenic and pleasant. There are buses from Kur to the resort, the way takes about half an hour. By the way, if you have a hotel guest card, local transportation is free for you.
In peak season, from early December to early May, an express bus runs from Zurich Airport to Laax on Thursdays, Saturdays, and Sundays. It departs at 13.00 from Terminal 2. Travel time is 1.5 hours and the ticket price is in the region of CHF 65.
There is free bus service between Laax, Flims, and Falera for all ski pass or hotel guest card holders. This does not apply to night flights, for which you will pay CHF 4-7.
If you're driving from Zurich, take the A3 highway to Sargans, then the A13 to Reichenau, then you're on a direct ascent to the resorts (15-30 minutes). There are signposts everywhere, so you're unlikely to get lost.
