As soon as you can, use real and relevant words. If your site or application requires data input, enter the real deal. And actually type in the text — don’t just paste it in from another source. If it’s a name, type a real name. If it’s a city, type a real city. If it’s a password, and it’s repeated twice, type it twice.
Sure, it’s easier to just run down the forms and fill the fields with garbage (“asdsadklja” “123usadfjasld” “snaxn2q9e7″) in order to plow through them quickly. But that’s not real. That’s not what your customers are going to do. Is it really smart to take a shortcut when customers are forced to take the long road? When you just enter fake copy in rapid-fire fashion, you don’t know what it really feels like to fill out that form.