For starters, carefully review the design of the puzzle. Remember that even the most complex charade has a solution, which, incidentally, can be done in just few minutes. Inspect all metal parts and small items. Many of them seem not what they really are. Also carefully read the job to the puzzle that is required from you as a result. Mentally think about how it can be done.
Now start to disassemble the puzzle. Try to think originally is the key in dealing with such problems. Complex puzzles usually have a very simple solution, so the first is to try unorthodox methods. Rotate the items in those parties that they, at first glance, can not rotate. Sometimes vision can be deceiving, and what I hope the creators of these puzzles.
If the puzzle contains items in the form of rings, try to pass them through the other parts. In most cases, they too have a deceptive appearance. For example, can be made in not quite the right shape, so at a certain angle of inclination will pass through the other ring. Experiment with different combinations. Put a few details together so that they formed one.
Do not try to use force to detail that, in your opinion, can help in the disassembly. In fact, every puzzle has a very simple solution that does not require significant physical effort. In most cases, by the way, to do light, even air traffic, allowing the puzzle elements themselves will take place exactly as they should. And try to remember exactly how you took apart the puzzle, because then you will need to collect it back, but it's not as easy as it seems.