Thank you for all your replies. I believe this thread isn't only useful to me, but also for many others who are on the same situation, following this thread closely day by day in search for a way to boost their daily finances.

Just explaining some points that could have been misunderstood:

• This thread isn't asking for passive income, big investment or risky activities, what means it doesn't include mining operation, gambling or trading;
• With avoiding competition I mean jobs or tasks which someone can start right after signing up on a site, without the need of waiting weeks or months to be hired.

So far by reading all comments I see it's really hard to find offers on the internet nowadays for skilled and unskilled workers. I think some years ago there was more demand as it was mentioned by some people the faucets and mrai captchas, which paid more decently than captcha entries now (0,5$ in btc for 1000 captchas). Furthermore there were signature campaigns without participant limits.

Actually the most interesting method that could be practiced by everyone without restrictions are the sites listed by @TedMosby (micro jobs), although I'm not sure if there is enough demand to make it sustainable. I worked on sites like this before (crowdflower) and made some money, but then they put tricky tasks disponible, with dubious results, reducing my accuracy. I don't know if they do that on purpose, but it's very disappointing.

The Publish0x idea is also nice, but I discourage copying and pasting part of other articles and if you write articles on your own probably 2$-3$ isn't compatible with this task.

There is also the weworkremotely idea by @malevolent, where there are many offers. This one seems good for professional workers disposed to work in direct contact with the public (charismatic individuals).

But thanks again everyone. As ideas are surging all the time, feel free to keep contributing to the community.

And if you want a drawing or logo feel free to pm me. Check my portfolio thread below:
Drawing Logo Design and Portfolio