You can buy some advertising space on crypto website or other website that have same topic as yours. You can also go to advertise website such as coinzilla or etc. Most of people think this is pretty effective, or just buy advertising on social media such as facebook, i think they still accept crypto ads.
You can also do campaign or bounty in this forum such as people above said.
I'm pretty sure that Facebook has banned crypto related ads just as Google has? It happened a bit less than year ago, if I'm not mistaken. So any paid ads will not go through on Facebook and some other social media websites anymore, so I guess that makes it a bit harder to reach the target audience via social media now.