My current workflow is to download cards at the end of every session onto both an internal hard drive (which I work off of) and an external hard drive. After culling, editing and uploading to a web gallery, all files are backed up from the internal hard drive to two external hard drives. As of lately, my backups have been on-site on the external drives, with one off-site storage of the edited .jpg files (i.e. my web gallery / order fulfillment site). But just recently I also purchased a Cloud backup solution to ensure off-site backup of not only .jpg images, but the RAW files as well. So my clients (and I!) never have to worry about lost moments and memories!
My new machine (which my amazingly wonderful husband spec'd and built for me), is screaming fast, and makes me wonder how I managed to get anything done with the old one!