(russian version of this post
It's simple technique, but very time consuming. At first, i place black (or dark) background behing the scene, put a camera on tripod and set it to manual mode with settings: iso at minimum (80), aperture to max number (8 in my case) for wider DOF and set exposure time to 5-10 seconds (i turn off light, make a test shot with flashlight and adjust exposure time, if it too low or too high). When i done with camera settings, i start continuous serie of shots, turn off the light and start to lit the scene with LED flashlight from different angles and distances, changing the lighting when i hear shutter sound from camera (Canon Powershot A650 with CHDK firmware writes RAW shot in 5-6 seconds, so i have enough time to move flashlight where i want). At first, i don't move flashlight during exposure time, taking static lighted scene, and when i got enough shots, i move flashlight while shooting, trying to get some nice light effects. When i got enough shots, i stop the camera, upload shots in computer and look at serie of shots, which looks like that:
Then, i sort all of them. Firstly, i divide all shots to 2 groups: dark and bright. Inside each group i sort shots by type of lighting: front, side, back, top. This sorting helps at processing stage, and i can easily exclude some shots from processing (these what looks similar). After sorting, i select one of dark shots as "base". Usually it is shot with good lighting at centre of scene and with dark corners and background. I load all shots in Photoshop as layers, and move base layer at bottom of stack. I set black masks to all layers, except base, so they become invisible. And now i start most time consuming processing stage. Starting from bottom hidden layer, i make it visible (by disabling mask - clicking with Shift key at mask icon) and invisible again several times, compare it with picture below. If i see some parts, which looks better than underlying picture (good lighting or interesting light effect), i add this part to final mix by painting mask using white brush with soft edges. For example, at one shot i like blue reflection at hat of big mushroom, but nothing more, so i add only area with this reflection. On another shot, i like good shadows of foreground mushrooms at wooden table, or lighting of maple leafs at background, or something else. So i go through all layers to top one, adding good features from some of them. After that, picture looks nice, and i do standard postprocessing steps: sharpening, noise removing, HiRaLoAm layer for better local contrast with highpass filter and finally, color correction and global contrast with curves.