For the best backup plan use multiple backup strategies.Former posters have already mentioned the best softwares for backing up your data. A good idea would be to separate data from your installation.
I have partitioned my HDDs in such a way that OS and installed softwares are separate from independent data like documents/videos etc
> I use Clonezilla (freeware) live CD to clone an image of my drive with the OS and softwares. An image also stores all your OS and software updates so you dont have to update everything from scratch the next time you reinstall (restore the image).Its like taking a snapshot of your hard disk.
I take incremental backups and store the two latest versions on my external HDD and archive the older ones into DVDs.
Alternatives
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Acronis (Considered the best/commercial-ware)
Norton Ghost (Commonly used in corporates/commercial-ware)
> I also use Toucan portable(freeware) to sync-copy folders with my independent data like audio and documents with my external HDD.
Alternatives
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> Microsoft SyncToy (considered the best)
Finally have a good data restoration software at hand to restore deleted files.(you never know when you ll accidentally delete or format your backed up files
) Restoration a portable and freeware app is what i use
Alternatives
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Recuva (commercial-ware)
I encrypt my passwords using TrueCrypt and store them in my HDD offline out of reach of the baddies. I have also written them out on a diary....just in case.
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You may want to make your own backup schedule depending on your needs ..but it pays to have an organized backup plan.