Why use abstract and vague rules of trading, they are so easy.

1) Identify the main trend, if it's a bearish or bullish one.

2) Trade accordingly, avoiding to trade against it. The trend is your friend.

3) Don't think the price is already very low and that it's time to buy. Prices can always go even lower.

4) Be careful guessing tops and bottoms. If you were wrong, jump out and assume the loss, instead of converting your move on a long-term one. If you insist in keeping them, avoid buying more to lower the median price, that is a recipe for disaster.

5) I know it goes against all the rules you learned on life (it's a violation of the rule of demand, that says that demand lowers when the price goes up), but don't think the price is too high to buy, unless it's clearly temporarily overbought or it was a fake breach of  a resistance. If it's on a bullish trend, the probability that it will keep going up is higher than the opposite. So, many times, buying higher has more sense than buying lower. Ex. I have little doubt that if bitcoin breaches clearly the 1156 top on bitstamp it will keep going up.

6) The rule is not to buy low and sell high. Buying an active on a bearish trend, going lower and lower, is a disaster. If the active is in a bulish trend, the rule can even be buy high and sell higher.

The hard thing isn't to identify the rules, but to follow them!