What I usually do if prices are falling most specially if the coins are very low, I would buy more coins from a much lower price and your total amount of couns would then be divided; the result would be lesser losses. Read or research on google about books or ebooks on trading.
Me too, i will take the opportunity to buy more coins that i know can be longer on the market and hold until the value pumps again. So in that case, in the future my coins have a great profit and my losses will be lessen.
This is very effective for bitcoin, but it is very basic for altcoin because it is not all good to hold, the popular altcoin movement seems very slow, most traders are more interested in shitcoin trade because the risk is proportional to the large income. I'm more interested in selling coins that do not have long-term potential and more focus on holding bitcoin even though it is experiencing a downward trend.