I think that people who are stuck at the level of 1600 standard need different type of training.
I suggest the following training
Before solving a problem take a pen and paper and simply write every legal move that you have.
I do not use a pen and paper but I trained myself to look at all the board in my head many years ago and even in my case it is better if I do it in case of not finding a clear solution because I believe that I could avoid at least one of my failures simply by using this simple trick.
see
http://chesstempo.com/chess-problems/43208I did not solve it for the simple reason that I did not consider Qf4 and both checks seemed the same for me so I chose one of them when I guessed that there is some win that I do not see when it will be easier for me to see it later.
I feel sure that I could solve it in case of simply writing all the legal moves of white.
The problem is considered by me as an easy problem and the fact that people including me failed to solve it does not change my opinion about it.
For me hard problems are problems that even after considering the right move you simply underestimate it and consider it as bad or problems that there are many lines that you need to calculate.
Uri