What tricks and techniques are available to me to help simplify and decompose dense prose? [closed]

Solution 1:

Could Thomasin's mournfulness now and Eustacia's serenity during life have been reduced to common measure, they would have touched the same mark nearly. But Thomasin's former brightness made shadow of that which in a sombre atmosphere was light itself.

If {Thomasin's mournfulness now} and {Eustacia's serenity when she was alive} could have been converted into the same units of measurement, they would have almost reached the same level as each other. But Thomasin's earlier brightness caused any brightness that existed in this sombre atmosphere to seem to be nothing more than a shadow.