Looking pretty solid so far. You've got some good base colors and selections going on. All you really have to do is shade the pits and recesses with a wash and add some highlights, in my opinion.
Edit -
If you're looking for specific advice, I would use a brown wash on the green armor, boney spikes and gold trim; and a purple wash on the tentacle bits. Your base armor color is pretty bright, so you can either wash the whole thing to darken it down a bit and then highlight it back up on the edges and rivets and such, or if you like how bright it is you can pinwash just along the dividing lines and in the cracks and pits. I would also work in a bit of red or pink on the tentacles to give them some more pop.
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