What is the process to review my changes in JOSM before uploading? I could not find anything online…
Data can currently be reviewed after it has been uploaded to osm.org. See this blog article.
If you want to know where you can select you data for review in JOSM, see here:
If you want to review your changes before you upload, you may send your changes as .osm file to a second mapper.
Depending on what I’ve done, I sometimes do a search for “modified” in JOSM to select everything I’ve touched in an editing session. Then if there is something selected that I did not expect I can go and examine it to see if I’d made an inadvertent change.
I also do that, but be aware that this will not show you deleted objects.
You may open a new layer and download the existing data (again) to compare with your version, for a single object you can press Strg+H to view the history. When it is modified, you can see what you changed.
There is also the mappaint style “Modified objects”, which highlights modified objects.
Is the “Modified objects” mappaint style still the best solution to review changes before uploading to OSM?