1. Chose you process/factoid - something relating to Ice, or cuddly animals is best - eg Polar bears (only recommend cuddling when very small), seals, penguins, Ice melting rates etc.
2. Make an assumption about its rate/size/numbers - but make sure its a big one that you think any change from will be shocking.
3. Do some measurements / send a TV crew / idiot in a Kayak out to provide a small amount of real data.
4. Issue press release saying [enter your process/population here] shown to be vastly [lower/higher] than expect, meaning [global warming is true/we're all going to die/my research needs further funding/we should all live in tepees in Wales/ Socialism needs to be enforced to be green]
Easy.
If you want to see how its done so journalists swallow it whole see the BBC brain washing children here and Telegraph here.