It is interesting how well-titled the play Trifles is because it certainly is rife with them. Yet, ironically these are anything but trifles at the end of the play.
It is arguable that the first trifle is the dirty kitchen towel of which the country attorney complained about. This may be a significant and foreshadowing trifle because of the answer that Mrs. Hale gives him.
Those towels get dirty awful quick. Men's hands aren't always as clean as they might be.
Since Mrs. Hale has an inkling as to what may have occurred in that house, this may be a clear reference to John Wright.
Aside from this first incident, more trifles show up:
The bread was set out, which may mean that the last fight of the Wrights could have happened near dinner time, prior to bed, and before Minnie snaps and kills John.
That there is only one compote of cherries after doing such hard work is significant of the state of the household, and how little produce was coming out of their farm.
Then comes the stitching which, with its erratic pattern, shows the state of mind of Minnie Wright. Shortly after that, they find the birdcage with the hinge pulled apart. This brings the women closer and closer to the final piece of evidence that would signal the motive of the crime.
When Mrs. Peters opens the cupboard looking for paper and string, they find the carefully wrapped body of a canary inside a box. This bird was Minnie's only companion, and her abusive husband grabbed the bird and wrung its neck. There is the motive of the murder: Minnie must have finally snapped, so she killed her husband in a similar manner.