Second: you should always buy at the lowest possible price try to buy the currency when it decreases
To the lowest levels and avoid buying on the rise or when it is at the top of the rise
They may go down at any moment and dramatically
This is really difficult, like catching knives? For me, it is much better just buy the dip, you can' predict exactly what's the lowest. Or you can also the averaging of your entry when you are buying the lowest level. Technical analysis is really important on this, like identifying the previous supports and resistances so you have an idea where to buy and sell.