Yeah I do the simple buy low sell high, but i've got time up my sleeve so i'll watch coins and research their projects and see if i can pin point any specific lows or can predict with reason fluctuations.
Like one coin i'm watching goes up and down 100% proportional to BTC prices but over like a 3 week period, so i find that one an easy one to profit from.
TLDR: Do research, try to find trends, take risks at coin lows (altcoin margins are better)