Take the train

"I travelled from Leeds down to Kings Cross and then walked across to St Pancras to check in for my Eurostar train. The journey across to France was quick and the time passed very quickly. The eurostar I was on went to Paris Gare du Nord - here you need to change stations to get to the Gare du Lyon. It's really well signposted and only a couple of stops on the metro.

At end of eurostar platform turn left, go down the stairs follow signs for RER LINE D - it's about 5/6 minute walk. Before the barriers buy your metro tickets. At the barrier you put your ticket in and collect it again as the barrier opens. The Metro will be heading towards MELUN/MALESHERBES or CORBEIL.  Gare de Lyon is 2 STOPS, then follow signs for station.  Total transfer time is 30 mins max from getting off the eurostar.  It is a very large station with 2 platform areas, all signs are in French and English, train departure platform is displayed 20 minutes before departure so plenty of time to find the right one.  Make sure you validate your train tickets in the yellow machines which are near the platforms. 

I then continued to Grenoble on the train where I was collected and transferred by taxi to Montgenevre. There are other options for the trains - you can travel from Paris down to Oulx in Italy (very handy for Montgenevre) or to Briancon (good for Serre Chevalier or Montgenevre). Another good tip is to get a eurostar to Lille as then you only have to change platforms to get a connecting train down to Grenoble (rather than changing stations as I did in Paris).

 For the return journey from Gare de lyon follow signs RER LINE D. The Metro will be heading towards ORRY LA VILLE or CREIL, again 2 stops and when you get off the metro head for RUE DE DUNKERQUE and GRANDES LIGNES."

• Take 'picnics' and drinks for the journey, food on the trains are expensive and not great quality.  There are plenty of little coffee/sandwich bars in the stations which are reasonable.
• 10 minutes before expected arrival time go to the loo on the trains - toilets are €1 each to use in Paris and at least 30 centimes/30p in regional stations (UK and French).
• Metro tickets are bought individually (cost €1.30 each) and are validated when you go through the barrier.  Buy tickets for both outward and return journeys at the same time each person needs 2 (put your return tickets in a wallet/purse seperate from the ones on the outward journey its really difficult to tell 'used' from 'unused' ones!)
• There are people selling metro tickets but get them from the machines - the people selling the tickets are doing so illegally and there is no gaurentee the tickets will work (remember its difficult to tell if you are buying a used ticket).