Here's a comprehensive explanation of the abuse of discretion standard of review in Horsford v. Board of Trustees of State California University (2005) 132 Cal.App.4th 359, 393:

“This description of the standard is complete, however, only if ‘beyond the bounds of reason’ is understood as something in addition to simply ‘irrational’ or ‘illogical.’  While an irrational decision would usually constitute an abuse of discretion the legal standard of review encompasses more than that:  ‘The scope of discretion always resides in the particular law being applied, i.e., in the ‘legal principles governing the subject of [the] action . . .’  Action that transgresses the confines of the applicable principles of law is outside the scope of discretion and we call such action an ‘abuse’ of discretion.’ . . . For example, a court could be mistaken about the scope of its discretion and the mistake could be entirely ‘reasonable’ – that is, it adopts a position about which reasonable judges could differ.  But a reasoned decision based on the reasonable view of the scope of discretion is still an abuse of judicial discretion when it starts from a mistaken premise, even though nothing about the exercise of discretion is, in ordinary-language use of the phrase, ‘beyond the bounds of reason.’ . . . In other words, judicial discretion must be measured against the general rules of law and, in the case of a statutory grant of discretion, against the specific law that grants the discretion.”

(Id. at p. 393; citations omitted.)  In simpler terms, “‘A trial court’s exercise of discretion will be upheld if it is based on a ‘reasoned judgment’ and complies with the ‘ . . . legal principles and policies appropriate to the particular matter at issue.’”  (Colur-Vue, Inc. v. Abrams (1996) 44 Cal. App.4th 1599, 1603.) 

          As you might guess, appellate attorneys generally prefer an independent review so that the appellate courts will pay less deference to the trial court's "reasoning."