Take a look at the Service board and try to find a signature campaign what accepts Newbie, Jr. Member, Member level users (and there are open slots). (These noob campaigns are usually not paying very much and some of those are not very reliable but still better than nothing.)
Write a lot of meaningful posts to reach the Full Member level. On this level you can join some better paid campaigns.
Sometimes you can get some BTC or other free stuff in the Games and rounds board (under gambling).
Please note that "free" BTC in the gambling section is rarely free.
You might wanna take a look at the altcoin announcements sometimes they are giving away stuff for free.
If you have some "sellable" skills you can try to get some smaller tasks (and bounties).
If you have some unwanted stuff you can sell it on the Marketplace.
Sometimes check out the Project development board for paying beta tests.
Keep your trust rating clean.
You can try faucets but IMHO that's wasting time.
Don't do:
Don't bring up ancient topics without a good reason. Vod and Co. will think you are just spamming for activity farming (you can get negative trust.)
Don't ask for loans (especially without a good collateral) because of those guys in the Lending board are grumpy ppl, so you will get only negative trusts instead of BTC.
Avoid the "Investor-based games" sections as this is a PC name for ponzi schemes.
Gambling: don't go there if not necessary
.
Do not invest into the latest and greatest stuff "with great investment potential"
Avoid IPOs, ICOs, ITOs. Those bastards in the Securities and Altcoin sections are all scammers. (OK, not all but 99%)
On the altcoin board do not believe a single word even when they are asking questions.
