Sometimes the simplest change can lead to the greatest difference. For example let's consider the Earth's temperature status. According to Climate.gov, even a 2-degree increase in global average surface temperature (since the pre-industrial era) results in a significant increase in accumulated heat and thus palpable global consequences such as seasonal temperature extremes, snow and ice reductions, intensifying heavy rainfall, changing habitat conditions for plans and animals, etc.. All this from a TWO degree change??
In September of 1848, railroad foreman Phineas Gage was impaled by a tamping iron, measuring 1.1 m long, 6 mm in diameter, and weighing 6 kg, through his left cheek and out of the back of his skull. Miraculously, Gage lived through the traumatic injury, even remaining conscious throughout the event, able to walk on his own strength, as well as able to calmly describe the scene to town Dr. John Harlow. After a month, although blind in his left eye and with facial weakness, Gage seemingly recovered physically, but the same could not be said about his mental well-being.
Dr. Harlow observed Gage regressed to a child's intellectual capacity, while at the same time exhibiting animal-like "passions of a strong man....(Gage’s) mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage.’” Harlow's observations were bolstered by physiologist Dr. David Ferrier's studies on essential brain functioning in animals. He concluded that the ironing rod pierced the prefrontal cortex of the frontal lobe of Gage's brain, causing profound personality changes, without other apparent neurological deficits (the ability to speak, walk, etc.). Phineas Gage's accident was random, traumatic, but also so extraordinarily precise: had the rod been any other shape or size, Gage's experience may have been drastically different, and neuroscience's understanding of the complexities of the brain would be greatly hampered.
Even the slightest graze of your finger on top of a still pool of water provides the catalyst for ripples. So, if you think massive changes are necessary to make great impact, think again. This is incredibly applicable when re-examining your presentation. Shifting an anecdote from the conclusion of your presentation to the introduction may add the impact you're looking for. Keeping your body still and using hand gestures only to emphasize major points will reduce audience distractions. These implementations will move your presentation from good to exceptional. Check out my video on Gestures and Stage Movements for more simple tips for profound changes.