[This question is very speculative as there is no definitive answer as such. But here are a few pointers.]
When communicating a certain era through design, look to fashion, history, power-influences and the zeitgeist in general.
A Case Study: Early 90s Clubbing Culture
For example, in late 80s-early 90s Britain, a "working-class" fashion trend which culminated in a mish-mash of influences from the Eastern-influenced hippie look seeped into clubbing fashion. This was probably a reaction as a result of Thatcherite policies which opposed rave culture and valued conservatism (Public Order Act - 1994) and the rise of corporate culture. At this time, mines were being closed down in Northern Britain also by the govt., which hugely impacted the region's economic viability. By adopting a "working-class" trend, subculture resonates its values in contrast to the super-power (in this case "Middle Britain"). At this time, dungarees, even boiler suits were not uncommon in clubs. The Hacienda club even adopted colours and patterns based on signage from health and safety standards. Interestingly, the nineties trend is prevalent again today even in music, possibly as a pastiche, or a recurrence of similar values held today.
Today we are still recovering from a worldwide recession, much like the eighties/early 90s. A back to basics mentality seems prevalent, hence the surge in "vintage", hand-made aesthetics and parodies of corporate visual identities.
In typography, the "undesigned" look is in vogue, with a lot of hand-made typography and lettering. I suspect that mono-spaced typefaces such as Inconsolata and Courier are also trendy too to a similar effect, but probably not for long. Aphex Twin's album art for Syro is an example of this, and supposedly this "alien" type was fashionable in the 90s also. The FF Meta typeface was described as the "Helvetica of the 90s" for what it's worth. Helvetica was very popular back then also, along with Frutiger and Univers. Have a look at Peter Saville album covers also.
As you can tell, trends are very speculative; for this reason, designers try to avoid them when possible. I hope this was of some help.
This book demonstrates an excellent resource for deconstructing trends from the 20th century: Subculture: The Meaning of Style by Dick Hebdige(1979)