You can usually see through body language, positioning, eye movement etc. where they're going to put it. The PK taker is always going to have the advantage, but you can hike that normal 12% save rate up to 20-25% if you really put effort into it.
The value is so low though, one or two saved...
There is a really good book on penalty saving written by some Dutch expert on the subject.
Before some tournament (2004, 2006 or 2008) Edwin van der Sar was visiting a talkshow who was also guested by the guy who had just released his book.
"Have you read it?" the author asked.
"No..." said...