Ironically, most of these tips do work, in some weird sense.
1. Always type with your non-dominant hand - so it's not typed in your handwriting.
Yes, there is a small chance that somebody has some app installed, able to get the characters out of the typing habits. But these applications work best only if they are installed at the victims computer. It works with a microphon too, but I would just install a videocamera instead of the mic: works better and doesn't even need that very expensive program in the first place.
2. Pick the right password - close your eyes and slap the keyboard at random.
Not really random, yes, but magnitudes better than "password", I guess.
3. Get hundreds of credit cards - never use the same one twice.
A provable secure method if you can make sure that every credit card is stamped invalid immediatly after first use. That is not possible without the help of the credit card company which proves it impossible mathematically too.
4. Defrag your hard drive once in a while - overheard a nerd say it somewhere at best buy.
The only filesystems where regular defragmentation makes sense are the filesystems offered by Microsoft. Now, if the drivers of these filesystem have a little security hole that opens above a certain point of fragmentation ...
5. For every real search on a search engine do a fake search - make it seem it's not you doing the search.
Has been shown (here! ;-) that it doesn't work as planed. It is also shown, that nothing works as planed, only as coded, therefore the chance that it works is above zero. I'll leave the computing of the exact value of "above" to beaver.
6. An infected computer is a vulnerable computer - make sure you wash your computer once a month.
The average PC is one of the best available dustsamplers. The multiple levels of encrusted residues of human emissions have high thermal isolation values resulting in unstable behaviors of the internal switches and therefore unstable bit patterns. This may result in excessive gashing of security holes which can only be resolved by massaging the main memory with a two-handed double-headed axe--blades preferably engraved with erotic scenes--orthogonal to the hairline.