Christians, even Calvinists, often act as though God is sovereign only over the big things. If something is trivial to us, we assume that God has simply left it to chance. But God governs over all things, regardless of how small. It is said that the devil is in the details, and he often is—but only by divine decree.
One man’s trash is another man’s treasure, so the things that seem unimportant to us may be important to someone else. This is alright, though, because all things are under God’s control. Even the affairs of microscopic bacteria in otherwise uninhabited parts of the world are divinely ordained. The universe is a grand symphony to the praise of the glory of God, and He has orchestrated every note (even the disobedient ones) to bring Him the most glory possible.