What constitutes an "attempt" to commit a lewd act upon a child?

"An attempt to commit a lewd act upon a child requires both an intent to arouse, appeal to, or gratify 'the lust, passions, or sexual desires of [the defendant] or the child' " " 'and . . . a direct if possibly ineffectual step toward that goal--in other words, he attempted to violate section 288.' " (People v. Crabtree (2009) 169 Cal.App.4th 1293, 1322.) " ' "Although mere preparation such as planning or mere intention to commit a crime is insufficient to constitute an attempt, acts which indicate a certain, unambiguous intent to commit that specific crime, and, in themselves, are an immediate step in the present execution of the criminal design will be sufficient. [Citations.]" [Citations.]' [Citation.] No clear marker divides acts that are merely preparatory from those initiating the criminal act. Nonetheless, 'the more clearly the intent to commit the offense is shown . . . "the more likely that steps in the early stages of the commission of the crime will satisfy the overt act requirement" ' of an attempt." (Ibid.)