You can save a lot of money doing a little research on car hire prices before diving it and booking with a familiar name.
If you’re flying to Geneva, you’ll have a choice of picking up on the French or Swiss side. French side is usually cheaper but it’s not that straight-forward. See here
You could easily save £100-200 shopping around
I’d recommend starting at the comparison sites. Try Carrentals first – as the broadest engine, to get a rough idea. It also might be worth looking directly at other sites, such as like Holiday Autos, AutoEurope or Rentalcars. Shopping around could easily save over £100.
Some car rental companies will give significant cashback on a booking, if made via Quidco or TopCashBack . 15% cashback can make a big difference on a hire cost of £250, so it might be worth looking at direct bookings – with Avis and so on – too once you’ve checked the comparison sites, as cash back may be much higher.
Snow chains?
Don’t forget to check the weather and add snow-chains to you booking if needed. Cars come with summer tyres on the French-side of Geneva. The number of times car hire companies have not had chains (or given me the wrong size) or I’ve needed to buy while I was away only to have to dump them has pushed me to buy a set of universal ones like these. Not as good as traditional snow chains but easy to put on I can use again and again on (virtually) any car again.
Don’t be ripped off on insurance!
I’d recommend buying your own car hire insurance, rather than taking it with car hire. I find I can get a full year for less than the price of one hire. I use Questor.