The previews are taken with lightest and darkest skin options. There are also four versions of each base shader that have specialized lighting: a strong bokeh (Bokeh) bokeh with reddish fog (Sunset) starry bokeh (Star bokeh), and a soft bokeh with halo effects (Cinematic bokeh)

Velvet has softer ambient lighting and more pastel colors than vanilla.

Rose is a softer color version of realism.

Realism is a strong filter that captures character skin and details well.

There are six main presets with simple bokeh:

Vertical previewer is in the list and will let you preview a vertical layout, and the aspect ratio previewer is set to the twitter crop (4:3) so you can get an idea of where to center your actors so they don't get cut off if you want to share screenies.The bokeh presets use ADOF or cinematic DOF, and if you want a finer control over the blur pane you can can use manual depth under either of those and place the blur where your shot needs it.The base presets use a combo of auto-blur (ADOF) and mouse-driven focus (cinematic DOF) you can toggle off the mouse-driven focus if you like, it just gives a nice customizable blur to the scene.

You can drop a light over your character's shoulder for some interesting glow.Use spotlights from a distance when necessary for a subtle highlight or color.Look for interesting lighting backdrops indoors, and look for dappled lighting to stand in outdoors - ambient light looks better in game than harsh spotlights from gpose.Experiment with making the character wet it anamnesis for a soft sheen (depends on scene lighting).Use the 'manual brightness adjustment' slider.They use MXAO, which can cause shadows in certain hairstyles.They have a lot of light artefacts and bokeh.They are mostly for portraits/closer shots.They are screenshot presets only and they are beefy and can cause your framerate to drop.I've been asked a few times to share, so here they are! This is my personal set of presets - I swap between them a lot depending on lighting and skin colors.

Ffxiv reshade screenshot presets