Double Bottoms are reversal patterns and often seem to be one of the most common (together with double top patterns) patterns for currency trading. Double Bottoms patterns are identified by two consecutive low prices of the same depth with a moderate pull back up in between (neckline peak).
The head-and-shoulders pattern is one of the most popular chart patterns in technical analysis. The pattern looks like a head (the middle peak) with two shoulders (two equal heiight peaks).