On 19th June, we started assembling a 750 pieces puzzle. And then almost everyday, the regular exercise once I am back from office would be to work on it. We'd spend almost 15-20-30 minutes everyday just before dinner. And exactly five weeks later, we placed the final piece in the puzzle, making the picture of a Moose Deer complete. The strategy first was to divide the pieces into as many groups as possible; and that is done by similarity of colours or patterns. So we took around 15 envelopes, and then created as many heaps of similar looking pieces, and each heap went into one. The idea being members of each envelope would be in close proximity of each other. This is particularly important that all similar tiles are together. One tile in wrong heap will cause a long search. This was not 100% accurate, though. There would be several disjoint areas which might have very similar colours; especially almost black tiles; and they are going to mislead. However, we can deal with such special case later.
One of the biggest challenge in the whole exercise is not to lose a single piece. Since you work part-time of it, it takes weeks to finish the project, and one single missing tile will spoil all the fun. Moreover, you have to save the work for the next day, which essentially means you have to reserve an undisturbed large area to store the half-finished puzzle at home (and if you can't then ensure you can easily move the work in progress).The photograph printed on the box was of very limited help. It was very small compared to the size of the actual puzzle; so looking at individual tiles it was very hard to guess which area they are going to go. Still then, the fun was in guessing and finally finding it right.
It'll be painful to disassemble it.