The 80s is known as a very dynamic era. The decorations must be really colorful so that your party must represent an environment of liveliness.
You can put up posters of different movies from the 80s, as well as celebrities. When all your guests have arrived at your place, just ask them to sit together and take a group picture.
If you are taking the pictures with a digital camera, then you can connect it with your computer and take out a colored print and pin it up on the wall. It will just make the guests thrilled as you will be posting pictures on the wall from time to tome.
You need to get yourself a costume as well that will represent the 80s period. In 80s, the fashion trends for guys were the frilly shirts, the super skinny ties and the huge op-art belts. For women, the 80s styles were the Bananarama style overalls, the headband layered mesh and lace ensembles.
You must wear the sported eyeliner, glossy lipsticks, the glittery eyeliner etc. This is all going to be fun as it is a change from the norms and I bet that you and all your guests will enjoy every bit of it.
No party is complete with the songs of that era and for that reason you need to select the best songs of 80s. You can put up a competition for all your guests to come and dance in front of the audience and the best dancer will get the prize of the best dancer for that year.
When everyone settles down and share of what is going on in their lives, you can serve the drinks with the glowing ice cubes in them and this will just take everyone by surprise.
You can gather a whole bunch of ideas from your friends and can incorporate them to make your party a real success.