How to reduce my Internet data usage on a iPhone? Any tips and tricks? (UK)?

I have a iPhone 4S on Vodafone and top up £10 which gives me 100mins 300 texts 50mb of Internet! How can I reduce the amount of Internet data being used? I need my top up to last at least a month!

Would be much appreciated if you gave me some help! Cheers!

Get a usage plan, Youtube takes alot of usage of buffering. Use Wi-Fi not 3G.

Yeah I have a solution like have you all checkout that video about iCloud chewing up the data. Mine was doing that. As soon as I deleted iCloud it stopped the data leak. I will backup the old fashioned way in iTunes.
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