prassō

This is the ordinary Greek verb for doing something, and it covers the whole span from a single deed to a settled habit of life. It can be neutral, simply naming what a person carries out, but in the New Testament it very often carries a moral charge, and more than half its appearances describe doing evil or wrongdoing.

Two shades of the one idea run through it. Sometimes it points to a particular act that was done, as when a court asks what a man has done to deserve death, or when Paul admits he does the very thing he hates. Sometimes it leans toward keeping something up as a way of life, which is why translators reach for the word "practice": those who practice such things, those who go on doing evil. The line between the two is a matter of context rather than a different word, so the reader should let the surrounding sentence decide which shade is in view.

Because it so frequently describes wrongdoing, some readers assume the word itself means to do evil. It does not. The negative flavor comes from what the word is attached to in a given verse, not from the verb on its own, which is equally at home describing good conduct or a neutral task.

This is a specialized use that grew out of the basic idea of carrying a transaction through. In everyday Greek it was the standard word for collecting what was due, whether a tax, a toll, or interest on a loan, and the New Testament keeps that commercial sense in a couple of places.

John the Baptist tells tax collectors to collect no more than the set amount, and in one of Jesus' parables a master rebukes a servant for not putting money in the bank so it could have been collected back with interest. The word here is not about wrongdoing or general activity but about bringing in what is owed.

When the word is used without an object and paired with a word like "well," it stops describing an action and instead describes a state, how a person is getting on. This matches the English expression to do well, meaning to prosper or to be all right, rather than to perform a deed.

The letter to the church at Antioch closes by promising that if they keep clear of certain things they will do well, that is, they will fare well. And Paul tells the Ephesians that Tychicus will let them know how he is getting on. In both places the word reports someone's circumstances rather than their conduct.