I have only two remarks to the document I linked before:
a) I do not recommend turning on "compute physically accurate caustics". If on, this option increases render time tremendously and is not noticeable in most situations. This should be turned on only when you have under water scenes or if you have a glass in close-up, or similar situations.
b) I do not recommend "optimize last render pass". True that it speeds up render but the result is not good, IMO.