Severe overuse of magic circles. Why not be more sparing about when these are drawn? They don't have to be used around every little itty-bitty minor use of magic --that's just annoying and well.. kinda makes the artwork embarrassing to look at.

Also, aliens that seem too dumb to own spacecraft. They just grunt and roar and crawl around like zombies with laserbeams and have seemingly no plan or motive whatsoever. There needs to be more "OH mY god tHey talk!". My favorite is when they are portrayed as having gentlemanly eloquent speech because I find that more intimidating in a villain.

I just wish people would step up to a bigger scale when it's needed or to a smaller scale for the same reason. I hate seeing big massive boats measured in thousands upon thousands of centimeters instead of just using meters or feet, and it's annoying when people say their height in hundreds of millimeters.

Or when knife-blade thickness gets measured in hundredths of decimal inches or weird fractional measurements instead of just using millimeters since it's a smaller unit.