Based on the following bounty request https://civitai.com/bounties/841/sith-pureblood-star-wars
Weight needs to be pretty high for this one at about 0.9, but you can go up and down as you please. The lower you go the less alien they look and it lowers the red skin tone.
Best prompts to use are ; red alien, red skin, yellow eyes, gold piercings.
Adding in star wars seems to always help with star wars concepts (who would have thunk :P) but beware of randomly placed lightsabres.
Also adding "human" in the negative prompts seems to help a lot.