Rules of alien-making:
1. Anything with recognizably human features or profile is less scary than humorously B-movie-like. Exception: Giger's Alien. Because that thing kicked ass enough with enough novel ideas to offset the crappiness. Nobody, outside of Giger and schizophrenics, will be able to repeat this performance.
2. It's not just out to kill people. NOTHING in the Universe is created specifically to destroy something it's never been in remote contact with.
3. Look at every mainstream alien ever made. Do something completely different, unless all you want is comments such as "Wow! That looks like (insert popular alien race here)!" Fortunately, the vast majority of these are crappy TV aliens, and fall under the category of #1- unconvincing.
4. If they speak English, you aren't cut out for this sort of thing. Quit before you are mocked senseless.
5. Aliens do best when they have one thing going for them massively, and that one thing only- Aliens don't have any real technology, Shivans don't innovate and are crap without their shields, etc. You can't be good at everything at once.
