My account grows because I am joining contests and comment a lot 30-50 comments at least.
I also post a lot.
I use steem-bounty, dpill, appics and palnet to do so.
I also use dust sweeper.
Delegating I did but I doubt it brought me anything and if you are low on SP I doubt it brings anything.
I also used steembasicincome to help about 15 people but am not sure if that brought me anything.
Instead of 50/50 I use 100 power up now.