Burn - This one's the simplest. Just send dozens of millions of Steem to @null. This directly addresses the distribution problem. Everyone left with stake now owns a significantly higher percentage of the Steem network.
This reduces the total amount of outstanding STEEM, which reduces the overall market cap - an important figure for marketing purposes (and ranking on the large index sites). It's probably not the best route as a result, because it makes the platform seem less important to an outsider.
That is certainly true if the price is constant. However, news of a burn can drive significant demand, and could easily offset the reduction in supply. If the price multiplies several times - not uncommon in the crypto world, as we all know - the end result could be a market cap that's far higher, despite the lower supply.
It's not clear to me as to which of these methods will be considered favourable by the wider crypto community, but burning does seem popular with the Steem community, judging by the many comments to this post. Personally, I'm leaning towards #6, though I'm aware realistically there'll be a bit of #2 and #3 as well.