ana_acer
Some of the best experience for cabin crew is Customer service as listed by many above, restaurant and hotel are usually winners as you are dealing with similar people in similar situations (ie usually in unfamiliar surroundings and with expectations of value for money)
Travel agency and airport experience are especially useful for obvious reasons
Any knowledge you can get of industry information such as airport codes etc will help you immensely
Another useful string to your bow would be first aid, you can usually take a short course with The Red Cross or local equivalent
and most airlines still appreciate foreign language skills
Best of luck, I started with Gulf Air 11 years ago I'm BA now (my 7th airline) If you get a good company that does longhaul, stick at it don't think the grass is greener it's usually 'same !!!!! different uniform!!!'
I've learnt that from experience!