What can community members do to contribute to Bitcoin's growth?

Talk about bitcoin with everyone you can. More businesses work with bitcoin the better.
Tip.
Organize donations from time to time for causes that also increase the visibility / awareness.
Make the community more help-oriented than scam/greed oriented (yeah, this is hard).
Learn from others, let others help this community, even if that would come from an alt ("shit?") coin.
This worked out well for dogecoin. It helped with the awareness a lot. Unfortunately it didn't help with the price.
But you have to ask yourself what you want: an asset with increasing price (hard to achieve by community alone) or a currency.