@RoseReveries shading on the tiled map can be hard, especially if you use texture-rich tiles. However, it
can be very easy, too, depending to the circumstance.
To shade properly, firstly you must answer this question:
Where your light source is positioned?
For RTP style tile users they must know that
default RM MV tiles light come from southwest, hence the shadow in the northwest. Lazy person like me like to use global light, in which light source came from the top, hence the shadow is directly below the objects without west-east skewness.
In your case, the light come from the west side (based on the small objects), therefore the shadow must be on right. This is already inconsistent with the building shadows which light source come from the south. My suggestion is choose one between west or south light source.
Again,
keep the light position consistent and you're basically good to go.
If you shade, you'll notice the tempation to use
gradient shadow. The rule is
only use gradient in non-flat object. The case in your map, please look at the alley and the roofs. My suggestion is remove the gradient and apply a flat shadow with only a pixel of blur. Please try and compare it!
The other characteristic is shadow length. Contrary to popular opinion,
in tile-based map, shadow length often follows the time setting rather than the object height or light source - thanks to the limitation of the tile size. It means that shadow tend to be longer in the afternoon and shortest in the morning or in the middle of day. If you feel your map is darker, it is probably because of this. My suggestion is keep the shadow short based on what time setting in the current map. Please try and compare it!
Give it practices, and you'll be a Shadow Master in no time!