Some time back every quarter we used to have PQRST Puzzle Championship. "Cihan Altay" was the author of these championship puzzles. He has come up with a great document which teaches puzzle solving techniques. He explain very beautifully the "Uniqueness" techniques (which is used by most of the best puzzle solver) in this document. He also explain techniques to solve Sudoku,"ABCD Connections", Dominos puzzles etc.
This is what "Cihan Altay" says regarding puzzle solving techniques.
Puzzle solving business is not an exact science. Just like most of the sports it relies on ability, experience and practice. And who knows how world champions solve their puzzles. You can not simply say anything you have to say about puzzles and then expect a newcomer to be the best. Still, this doesn’t mean that there are no facts on solving puzzles that will make anyone a better puzzler (If we are talking about championship level play, “better” will mostly mean “faster”). This effectively distinguishes puzzles from most of the sports.
I’ve written monthly columns on solving techniques in Turkish puzzle magazines for 3 years in a row, always hosting a different puzzle or a different technique. Facts, mentioned above, seem to attract more attention because they can easily be understood,accepted and used immediately on a puzzle. But, half of the techniques presented insights and tips on how to solve a puzzle rather than giving facts. This article will give examples from all, thus tying puzzles back to sports again. Whether solving puzzles is a sport or not is another topic.