Step 4: Make up some guff about the end of the world as we know it unless the monster is prevented from mating with the heroine
Step 5: Include entirely superfluous sex scene for the purposes of bumping up the certification rating (as the film won't be scary in itself to deserve anything beyond a PG)
Oooo!
Ahhhh!
Step 6: Involve a stupid accident which could have been easily avoided, but which somehow leads to things going in the alien's favour
