Mesper tell me, how are you doing shadows and light ? Are you using layers in photoshop or maybe using "smudge stiuk" ? I attach image this tool.
Well in fact i'm using various techniques, often mixed...
OK, please forgive me but I'll focus on just one question: shadows (matter of time... light effects are more complicated and not so easy to describe),
and will describe one of most straightforward and easy but still efficient and useful technique based on underlaying layers.
Let's say we want to add shadow on cloak/coat from sword's scabbard.
In this particular case I'll use special / additional "SHADOW" layer to which later on I'll apply standard Photoshop shadow filter.
This type of SHADOW layers I'm usually setting into multiply mode. But in some cases you might want to change / experiment with layer opacity modes, it might be crucial when background layer (in this case coat) already got some special effects/textures applied.BTW - layers descriptions are in English (hopefully without errors;) just to make these more understandable for majority of forum users, though normally I'm writing descriptions in some Polish-English mix (in order to keep these as short and meaningful as possible).
But the point is that I'm ALWAYS using full/self-explanatory layer descriptions. Yes, it cost me a lot of time during work! But then later when/if I'm modifying graphic, or just want to re-use some nice effects or even "import" some parts it proves to be worth and saves a lot of work.
Then I'm using also some "directional" and "location" marks - like "R" for right "C" for center - for more easily recognition - for example you might have top, mid and lower part of armour on left and right arm. Then some belts/straps linked to each part etc.
Then there are some other marks vide ">" or "UP" for ">L" etc.. which are telling what is the "target" or direction of particular effect. In this simple case we have just "SHADOW>coat", but for the other figurine the same shadow from sword might "land" also on some armour, leather tunic, shield etc...
So in such cases there might be several shadow layers, each with DIFFERENT settings (size, colour, opacity etc.)
"oC" layer stands for overlay Colour - special layer which in this case just changes a little saturation (in such case it's always worth to check SHADOW layer opacity mode to avoid potential colour space problems).
You might ask - why adding special layer instead setting good/needed value from start. Well, answer is simple - it might be used (switched on/off, different settings etc.) later for modding, but that's another "story"
Here you can see "SHADOW" layer shapeTo make it more readable scabbard color/effect layer as well as cloak effects are removed, then shadow layer, which originally is 100% black here is 50% opacity
As you can see shadow layer is shaped / trimmed so shadow filter effect will NOT exceed wanted area and will not impact other parts
For example in this case we don't want to have shadow outside the figurine contour (right side). Then the left side of shadow should be little delicate / smaller as there should be bigger distance between this part of scabbard and cloak.
In more detailed or sophisticated projects there might be more then one shadow layer and with very different shaped for just one "shadow-source" part.
Now, having properly placed and trimmed shadow layer we may apply Photoshop shadow filter (I have Polish localised version, but it's basic filter so I believe that there should be no problems).
Note, that shadow colour is NOT black - it's dark red/brown - it looks better, more realistic on cloak, especially when cloak additional effects and textured are applied.
It is good idea to keep unique shadow directions (according to the light source) for all shadow layers.
You might use Global check-box to do it - it might be useful when you are changing figurine positioning. However I do prefer maintain "manual" control.
There is more functions / parameters - these may vary in some other graphic programs and PS versions - but in general are pretty much the same.
It's fun to play with these settings and observe changes, but after some practice you will now by heart what settings are simply the best for particular job.
Actually I'm not messing too much with these setting each time I'm working on a new figurine. In fact, being lazy I'm using some well tested settings and using macros for automated adding some most-common effects or just copying styles between parts of figurine or other figurines.
Well, done!
Hmm... it's (as usual:) much easier and quicker to do then describe...
Of course for different parts of figurine, depending for example of distance between parts or surface, other settings should be used.
In some cases "layer-based" shadows just don't work or are not enough. But hopefully in such cases there are other techniques, which might be used instead or together with layer-based shadows.
Hope you will find it somehow useful