Biggest thing for promotion (without self gain) I would do: is make it easier for "people on the street" to be able to mine/access coins. This can range from adjusting the algo on bitcoin so that a miner that is built in a wallet has a relative chance of actually successfully mining.
That way, its "1 click" for people on the street to be able to figure out...without having to sweat things like figuring out "what is ASIC", hash rates, what is a pool, etc, etc. (The ASIC/pools obviously would still have an edge, but a normal computer at home would have a reasonable probability of actually mining their own coins).
If you get people on the street to be able to do it....then you will gain mass acceptance. As it is now, most crypto coin mining is limited to the world of Geeks & Techno-Nerds.
Side note: If you get a coin that is promoted that actually caters to the "dumbed down" audience of main street normal people - and it is promoted heavily without anything wacky (i.e. 50% pre-mine by developer, etc) - I think it will replace Bitcoin just like Facebook replaced MySpace & LinkedIn.