Depends on the coin, if you wait the long the developers will dump and run away with your coins! Assuming you have picked a good one with a good solid team then yes patience is the key. Give devs time to produce the product and then you will see a big price rise.
Or the product will turn out not to be as good as they advertised. The thing with most alts is if you cash out early you have 0 risk to get your profit whereas if you wait too long a competitor may pop up or the team turns out not to be able to deliver as much as they promised.
Even good teams with good ideas can fail.