A few observations about Romulans from 'Balance of Terror' and 'The Enterprise Incident'

[the G-man]

Of all my pet peeves about post-TOS Trek, the "aliens have funny foreheads" trope was/is the biggest. Just because it worked for the Klingons didn't mean it had to be used on every other race.

 

[Ssosmcin]

I saw the production logic in it, though. Forehead appliances were easier to grind out on a weekly, faster to apply than something more realistic or complex and you didn't have to ask guest actors to shave their eyebrows for a one shot. I gather that was one of the reasons behind the shitty Romulan designs.