The main thing I remember (I didn't worry as much about performance back then) was when I was grabbing a replacement from a pile of ribbon cables we had in a box, the wider ones were for SCSI, the narrower ones for IDE.

Then SCSI-II and SCSI-III and ATAPI/UATA/PATA cables came along and started making the ease-of-identification based on just visual traits a lot more difficult.