I've been wondering how to go about describing different alien species' appearance. How much depth should I go into when describing them? I don't want to be like "And it's got a rigid plate protruding from its head at a rough 45 degree angle and it has three eyes on either side of its head that are spaced about 8.5 centimeters apart and..." But then again I want people to know what these things look like, what do you think? Admittedly I'm more of a fantasy reader than sci-fi but my stories always come out as sci-fi, so maybe I'm just lacking in good examples. As a further question then, what are some decent sci-fi novels that could help me in this department?
Suggested options: I wondered what depth perception looked like out of three eyes, and what kind of planet would cause appendages protruding from one's head to evolve? Crap! I hadn't planned on that thing having an eye in the back of its head. Surprise was out, I would have to deal with those disgusting appendages on its face head on. I laughed at my pun, what else could I do under the circumstances.
Well that's the problem, I imagine you've got a weird image of some stupid looking creature in your head and in order to give you a better idea I'd have to go into a very specific and accurate description. Even then I'd only create a vague sense of what this thing looked like. Spiders have got eight eyes so I'm pretty sure my aliens can get away with six.
But that's not Ginger speaking. It's your character thinking, showing the reader the appearance of the alien through the character's observation and impressions of what s/he is seeing. In this case, confusion as to what line of evolutionary events would result in that end outcome. Not only does this tell us about the alien's appearance, it also talks to us about the thought process of the character.
Take the description you have in mind, and the circumstances of the scene and you can show it any number of different ways. Those six large blue-green eyes that dotted the sides of its head were endearing me to my new friend. I couldn't decide if the plate on the middle of it's head said it was more closely related to a Pachycephalosaurus or a Pystira Ephippigera Jumping Spider.
*Applies palm to face* Sorry, @GingerCoffee, I thought you were questioning the credibility of my creation - your post makes much more sense now. That is decent advice, thanks!