The January 2010 Tactics Time features some great positions.
One type of tactic that some chess players have a tough time with are one square queen moves.
Another type of tactic is one where the piece moves backwards.
Be sure and consider these types of moves when looking for the best move.
Life Master Brian Wall even advocates looking at every legal move to make sure you don’t miss something.
Another tip relevant to the positions here, is that sometimes there is more than one way to make a recapture, and they are not always the same. Make sure you look for the best recapture.
Studying chess tactics is like going to the gym. You have to do them on a consistent basis to really get the most of out them. In position 5 I was really rusty, and was embarrassed I missed this mate in 2.