If you’re interested in steampunk, Nader Elhefnawy has a well-thought-out article on it up on the SFWA site.
I particularly like the way he acknowledges the role of nostalgia without automatically dismissing nostalgia as something that must always be inherently bad. Yes, the steampunk vision of the past conveniently overlooks the less-attractive parts of the period, but the flip side of that coin is that it valorizes the attractive, selecting out qualities we may be losing/have lost in this day and age and trying to resurrect them. Plus, Elhefnawy puts the current era in context with the past in a way I found very eye-opening, characterizing this as the post-apocalypse of the Victorians, with WWI as the apocalypse.
Interesting stuff. I recommend reading it.