I've found that writing my dreams, including every detail I can remember, helps a lot to remember my next dreams. In fact, ever since I started posting my dreams here, I've been dreaming much more and remembering each dream more vividly.

And yeah! I often dream with aliens :O And weird thingies. I didn't know Lovecraft until someone mentioned that my stories are very similar to his stories. Then I read his stories and realised that many of my dreams and much of what I find interest in looks scarily similar to Lovecraft's fiction.

I dreamt once that I was running away from a witch who summoned some slimy worm-like parasites, and used harmful traps with tentacles. But I've never actually dreamt with humanoid aliens. They're always parasites, microscopic or have incomprehensible shapes, like the one time I dreamt with ones that had no shape and were like 5-dimensional. You couldn't see them but they were there and they affected you in ways that you understood but could not avoid. They were like mental parasites beyond physical form.