the strategy you use in buying BTC is also the kind of strategy for altcoins but most of these people will just say buy low sell high.
seem a very simple strategy when a person hears it. its the kind of words that will encourage a newbie to actually invest in all kind off assets as long as they see the price is already cheaper compare to its price last week.
i think an investor should just look at the price in the 3month chart and use the RSI to determine whether price is good or not. deciding to buy low sell high is probably clear from that birds eye view chart.
Mate, the strategy for trading Bitcoin may not be the same for altcoins. There are market Trends and chart patterns, there technical and fundamental analysis used, very important when trading; LTF/HTF, Daily/weekly/monthly averages also makes trading easy etc.
Now, Bitcoin has it own trends, moving averages, resistance and support levels at certain time which may be very different from many altcoins, and altcoins trends, moving averages, resistance/support levels are never the same.
even with each altcoins. In conclusion, trading requires basic knowledge and experience to succeed.