Going old school is sometimes the best remedy for a creative block. Here is a list of the must have items to create that perfect retro chic look and feel on your next design project.
Easily the biggest seller of the retro look is grunge. Rust, grunge, dirt, stained paper all add to the feeling of that bygone down and dirty era. Have a look at http://www.targetscope.com they have a great example of the dirty look you are after. Stained, crumpled paper, jazzy music all sell the idea that this is a retro design. They also have a great example of a retro illustration that bolster the military theme and conscription era vibe. Check out http://www.fivecentstand.com as well, as the have also used the 'been-through-hell' paper look to give users a authentic feel and vibe.
Old photographs of period people and clothing, aging signage, technology (radios, cars, black and white televisions) and those ideal female images working hard in the kitchen all create the appropriate atmosphere. If you cannot find the right photographs, why not get all DIY and create exactly what you are looking for. Check out http://www.custom-design.ch/custom08/index.php for a stunning retro TV. Just remember to age whatever you use so that it fits in the period.
Pop art can also be retro if you are looking for a more upbeat and vibrant look. Remember that nothing says pop art like unnatural skin shades, soup cans, canary yellow hair and half tones (Remember Roy Lichtenstein, Andy Warhol and David Hockney? Check them out, and their work, to know exactly what we are on about). Bright colors, strong themes and social commentary are the starting points of pop art, so do it justice and follow suit with your design project. Please for all things good and gracious, don't go overboard with the crazy colors. Moderation is your friend with this, as a step in the wrong direction could result in Fauvism.
Check out period movie posters, they are always a great starting point. Hitchcock's 'Dail M for Murder' and Edward's 'Breakfast at Tiffany's' are exactly what I am getting at. The combination of those angular fonts with the strong use of color, namely reds and yellows, is typical of this period in movie history. As I have said angular fonts along with handwritten fonts, with slick curves, and stronger almost military fonts dominated the typography field during this time.
There you have the definitive guide to retro design, you can also check out Smashing mag's views on this topic here http://goo.gl/cu6aV. Remember to spread the word and keep on designing