Personally, I find that being nice and ethical is the best way to get a reputation for being nice and ethical, though your mileage may vary.

I don't have a personal statement to make about my strategy for gaining a reputation for niceness. Partly because that is a reputation I would prefer to avoid.

I do make the general, objective level claim that actually being nice and ethical is not the most effective way to gain that reputation. It is a good default and for many, particularly those who are not very good at well calibrated hypocrisy and deception, it is the best they could do without putting in a lot of effort. But it should be obvious that the task of creating an appearance of a thing is different to that of actually doing a thing.