I try to buy whenever I can. Also depending on what the price is though.
If I think that the price will go down in a couple of days, I will wait a couple of days before buying.
I also do this but I try to do it on the safest way possible, I do not buy with high prices of course and I also look at the daily market so I can see what is coming.
You always have to look at the market if the market is not good you should not consider investing in it.
I only buy when I have a good feeling about the future and I think its gonna rise more so it will be profitable for me.