It's always worth building a portfolio of bitcoin and altcoin. Technical analysis is good for coins with larger market cap, but it may be difficult to perform an analysis on new/small caps. For altcoins, look for technology that really stands out or something that you're interested in; I personally like Ardor, Golem etc., but there are plenty others that have huge growth opportunities as well.

Lastly, always manage your risks! It's always better to miss out on an opportunity, than to lose everything in a poor investment.