When deciding in which coin to invest you can either blindly follow suggestions by others or make your own informed descision based on some criteria:
- What problem does the project attempt to solve?
- Is it a solution looking for a problem?
- Is there active development behind the project? (check Github activity)
- Has the team produced anything but a whitepaper?
- Are there established competitors which are much further into delivering a working product?
- Cross reference developers against previous scam projects
- Current market capitalization of the coin
This is a great suggestion when it comes to deciding what coin need to invest, but of course its on you on what you want and need to invest to a coin . Some invest to ETH and BTC because they are on top of cryptocurrency, some are risk to new ICO or coin that they think have a promising and potential to grow in the future. Reading to the threads and being involved to discussion will help you to choose good coin to invest.