Well, saving normally would work, as long as the place you saved at isn't inaccessible when the changes are applied, because then you'd be stuck. If you use save states, you can't really see the changes, in your map for example, unless you exit the map and enter it again, by warp or connection. However if you edit the events of a map, some warps won't be accessed if you load a state directly to that map. I'm not sure if you understand what I mean, but the quickest and safest way is to just use save states to save in a house or a pokémon center that you won't edit. Once you get out of the building all changes should be visible.