Well, considering Harry Potter's ability to think on his feet. If Aayla Secura is in a situation where she's trapped, perhaps in a magical maze created by some evil wizard. Harry could use his invisibility cloak to get close undetected and then use the spell 'Alohomora' to free her from whatever is binding her. He has a knack for getting out of tough situations himself, so he'd apply those skills to save her.
In this fanfiction idea, Harry Potter might save Aayla Secura through his knowledge of magical artifacts. Let's say there's a cursed object that is endangering Aayla. Harry, having dealt with various cursed items in his own world, like the Horcruxes, would know how to neutralize it. He could use the Sword of Gryffindor, which has the power to destroy dark magic, to break the curse on the object and thus save Aayla Secura.
In a possible fanfiction scenario, Harry Potter might use his magic skills. He could use a powerful spell like 'Protego Maxima' to shield Aayla Secura from an oncoming danger. Maybe she's being attacked by dark forces, and Harry, with his experience in fighting the dark arts, steps in to save her.