Hi African Photo,
I have exactly the same setup as you. 7D, 430EX II and 100L.
I shoot mostly at 1/200th, F11, ISO 200 and Flash in ETTL mode. I do alter the flash exposure compensation up or down a notch or two depending on background / ambient light conditions but really, it depends on what you're shooting. If you're in a controlled environment, you could easily go for Manual, bounced or off camera. Out in the field though where light is changing all the time, I find ETTL works for me with as mentioned, a quick adjustment to output as and when needed.
This example shot using the above kit was taken using ETTL with the FEC ramped up a bit due to the white BG. I used a large softbox diffuser (which as of yet I have not got round to custom building a more appropriate diffuser)