Step by step
COMBINE THE BEST OF YOUR FLASH-LIT IMAGES TOGETHER IN PHOTOSHOP
Combine and align 1
Highlight the images in Adobe Bridge that you want to blend together, then go to Tools> photoshop> load Files into Photoshop Layers. Next, go to the Layers panel and shiftclick between the top and bottom layers to highlight them. Go to Edit>auto-align Layers, choose Reposition and hit OK.
Mask and reveal 2
Hide all but the bottom layer, then reveal and highlight the layer above it. Hold Alt and click the Add Mask icon in the Layers panel to add a full black mask, then grab the brush tool. Choose a soft-edged brush tip and paint with white to reveal the part of the hidden layer that you want to use.
Blend the light 3
Carry on working your way up the layers (change the layer order, if necessary), adding masks and painting white to reveal. Once done, make a new layer on top of everything and grab the Clone tool. Set Sample: All Layers then use the tool to tidy up any messy areas to help clean up and finish off.