To become a successfull trader you will have to buy the lows and sell the highs.
That said, this is easier said than done.
In my eyes the only way to make the right decisions is being well informed.
Doing your research about the coins you are willing to invest in is very important.
Personally I try to read many articles and attending to Bitcoin meet ups when I have time.
Recently I discovered some free software that predicts the future movement of several coins.
www.cryptoforesight.orgIf you are to lazy to do good research, the chance of becoming a successfull trader is very small.
Don't give up trading if you made a few bad decisions, if you stick to trading you will learn new things every day!