Take a look at this thread about unveiling parties:
http://forum.portraitartist.com/show...4030#post24030
Though that party was held after the host and hostess had their painting, I made arrangements with them beforehand to give them a discount for holding the unveiling party for me.
(I also very much wanted to do a full length composition for this pose and they initially felt they didn't want to pay for the difference between that and a three-quarter. The discount helped them get the full length portrait and helped me get a portfolio sample with the composition I felt looked best.)
I discounted 12% of the full length double price. Since the unveiling party I have signed a contract for another double portrait for a woman I met at the unveiling party, and other commissions may still come of it down the road.
I think such a high discount only make sense if the attendees will be a group of potential clients that you would not be likely to meet otherwise, and if they are the right group of people, which it sounds like your party would be.
Here's what I had out on display: seven framed paintings, my portfolio book out on a table, business cards and a guest book. I had a friend of mine go around and ask people to put their name and address in the guest book and chat with them to assess their level of interest.
Every experienced professional portrait artist I've talked to tells me that commissions come from word of mouth in this business. Any "advertising" that builds on relationships (like parties) is money well spent, in my opinion.
As far as framing, presentation is everything. Do whatever you can to show your samples off at their absolute best. As they say in any business, it takes money to make money. Investing in nice looking frames for your samples is well worthwhile. Spending fifty or a hundred dollars on a frame can make the difference between having a portrait sample look like it's worth a few hundred dollars or looking like it's worth a few thousand dollars. Once the samples are framed they'll look good anywhere you show them in the future. Working in standard sizes allows you to re-use the frames for future samples or as "presentation frames" when you deliver a portrait to a client.
Check out JFM frames:
http://www.jfmenterprises.net/ Their quality is good and their prices are great. Peggy Baumgaertner and Karin Wells buy their frames there, as do I. You need to have a state tax number that authorizes you to buy at their wholesale prices, but that's something you should do anyway.