How we do one thing is how we do everything. If you notice someone who tries to cut corners or has questionable ethics when it comes to certain actions, chances are they do this in other areas of life too. Watch for any red flags…if something seems out of character from someone you are acquainted with, maybe you don’t know them as well as you think. That’s not to say that mistakes don’t happen and that everything is calculated/done on purpose, but it is something to be aware of.
Also, remember that actions speak louder than words. Many people can talk a good game. Talking is easy. It’s the follow through that is the hard part. Watch what others do and how they act (especially towards others who cannot help them in the near future). If you can see through their words and focus on their actions, you can see what a person is truly about.