Use からして when you take one piece of evidence and make a broader judgment about a person, thing, or situation. The evidence is often the first thing you notice, and the conclusion may be about the whole. For example, seeing someone's messy desk, you might judge their work style. It is often used with negative evaluations, but can be positive too.

This expression is somewhat formal and is common in written Japanese, news, and speeches. In casual conversation, you might hear it, but it can sound a bit stiff. It is not rude, but it is not a casual chat word.

Compare with から言うと or から見ると, which also mean 'from the standpoint of' but focus on perspective, not evidence. からして focuses on a sample or clue that represents the whole.