I was working as a video editor at a Digital Marketing Agency, that was testing TONS of different ads.
We discovered that the best performers were the ones that didn't look like professional, high-production videos. Mostly it was UGC, people filming with their phones, reviewing the product, and telling their thoughts/experience.
Also, comedy, and satire, worked really well. Remember that people on these platforms are there to have a good time, mostly. So it should look like native content. Start with a meme, a cat, or something absurd (like we had a Jeep drive over sunglasses, for a sunglass ad to prove its durability). Even typos in the first 3 seconds performed better than the same ads without typos.
Of course, it depends on the niche. It was performing well for us for eyelash products, sunglasses, and protein coffee.