There are many ways to go about making a low poly. The only way that is the right way, is defiantly what works best for you! However in some case, is definitely worth exploring new ways of making things. Specially if you are short on time and have a lot of low polies to build. This video focuses on creating the low poly for an organic architectural modular piece.
The goal here is to make sure that the low poly retains all the silhouette from the high poly. And that it looks just as good, if not better than the high poly. For that purpose i am starting using a decimated version of the sculpt, using the decimation master in zbrush. And then manually cleaning the model.
This is bit of a tedious process. For which is handy to do a few things to speed things up. By using hotkeys, i go into full autopilot mode and clean through the model very quickly. In this video i am using a lot of my custom scripts. For this sort of thing is important to understand that we only are interested on keeping the edges of the decimated version, anything else that is not helping the silhouette on the model, such as flat surfaces are going to be cleaned up, reduced and treated properly. I do a lot of this with vertex painting in mind. One thing i did not do a lot of are "test bakes". The only way you will know if you are reducing the model properly is by trying out test bakes. You bake your normal map, and you keep reducing. Rinse and repeat. It is also a good practice to have some version of the high poly decimated in the scene to help you see what needs to be constructed and kept intact.
I also want to mention that i am not a fan of jumping between programs too much. Which is why ive developed such a strict way to build these low poly models all within maya.