If you have skills like doing signature campaign codes and design, or handling campaign management, then just post on
Services there are lots of people looking dor this skill. There are many already but you can always start and gained trusted clients later on.
All of the things like that can be learned once you are willing and courageous to have that skills. Skilled people are the most probably to be accepted in the signature campaigns due to the service that they can give and those hardships and effort will become worth it once you have the confidence that those clients are looking for. We are all started from the bottom and it depends on us on how high will our ambition will bring us.
I suggest not focusing too much on finding a freelancing activity that pays in Bitcoin.
Try to focus on those fiat payments then have some of your earnings to be allocated in buying Bitcoin.
Your first option is to find freelance works established in your country. That way, you might be convenient in the application. There are BPOs who are also looking for freelance workers so try looking at it.
This is effective because I know someone who worked for a long time just to but BTC as his asset. Although he is working and earning fiat currency, he is already studying about cryptocurrency, especially bitcoin, and now he is not working anymore. He is just manipulating all of his asset and earning profits that is much larger than his salary before. Keep on doing freelancing and earn experience.