I think what you need to do is to be watchful of the kind of tokens you buy or get as a reward. Not all tokens will get listed on an exchange. There is time that some dev and team just want to test their idea on blockchain and they just need people to do that, after that they drop the project.
i totally agree, you should ALWAYS check the team, check the project details and most important is to check the team or company's past projects, do they abandon old ideas fast? do they have like long time support for couple of projects/service
no matter how small or big this is, but the history thing is really important, some very rare times team will be their first succeding project, but would you really afford to invest in such small opportunities, most of us can't so better take lower risks with old teams, because big risks here means losing 100% of capital