Peregrine wrote:If you want the best looking knight avoid
OSL (and LEDs, if that's what you meant) at all costs, 99.9% of the time it looks like

and runs the model.
Eh its pretty subjective. im sure some people get a bit of a chub seeing
osl considering how many people do it. but i agree i dont think it looks good 90% of the time. fantastic on dioramas (when done well and in moderation (or if it was specifically stylized like some of the massive voodoo stuff) but not on game models.
Base: realisticly a titan would sink into most terrain, for a mossy forest,
id sink the foot in a bit using greenstuff, maybe a foot skid like you suggested. also broken trees. if on a stone slab have it cracked where it stand to simulate the weight.
Primer. i would avoid trying to simulate cloud cover.
imho it wont look right on a table. proper zenithal highlights should get you most of the way there.
for weathering, chip areas that make sense like the chainsaw or claw hands foot and knee pads, soot up or heat color the barrels and smoke stacks, you can also add grim streaks to pipes connections and access panels too.
Specific techniques you will need to look it up depending on what tools you have and what you feel you will be able too do.