This doesn't really apply to academic conferences, which tend to have a more subdued atmosphere. (And you don't control the environment you present in, and there will be multiple talks in the sessions.)

I am on board with "hook them from the start", but you have to change it for an academic crowd. They will bristle at trying to be sensational. In an academic computer science context, it means put your conclusions first, along with your best results. People may tune out after the first few minutes, so you'd better tell them the most important stuff right away. The rest of your talk is then supporting and explaining how you achieved your best results.