In many instances, we can satisfy our requirements with the use of a text editor and browser; the latter's device mode (or responsive mode) will play a big part in creating perfectly valid queries that will suit many sites.
However, there will be occasions where this won't be enough. We may need to rely on additional help to support media queries for a particular project. One must ask, though, if this is really necessary, and not simply an excuse to be lazy. The media query support in recent browsers is very solid!
This said, if we have to use outside help, then there are plenty of options available online. Let's take a look at a few examples: