That's a great question. I'm learning as I go, but I think it's somewhat of an art. You try different things in different situations and find something that feels right. I can't answer for you, but I can show what I did with PIVX:
(That's from my copy of the spreadsheet I linked to in the original post). I bought 6k PIVX, starting staking and eventually sold 1k. Then I sold another 1k higher than that to get all of my initial investment back, plus a nice profit. Now I have 4k PIVX essentially for free that I can stake and keep long term. Obviously, it won't always work out that nicely, but it's a great example of when things go really well.
Some of the bitcoin I got from selling PIVX I used to buy Golem which I road up a little wave and sold for profit also. It's fun when all the candles are green, but when things go red it can be rough. I held all my bitcoin from $1,200 in 2014 down to the $250 range. Being emotionally involved isn't helpful for profit.
Just some random tips for beginners:
Emotion really kills the profits. Makes one sell low and buy high and that is when your trading account gets slaughtered. Have tight stops and don't put all eggs in one basket, cut the losses quick and let winners ride but don't hesitate to take profit!
And one more, if something is getting hyped from the the rooftops by many people, you're probably buying a top as they are unloading. Wait for a pull back, this time you can spend on actually reading about the project.
Excellent advice. :)