All the general swingers etiquette guidelines should be followed but at parties there are some additional rules that should be adhered to. It is understandable for those attending a swingers party for the first time to be nervous but remember that although it is acceptable to drink socially you should watch your alcohol intake as you aren't going to be able to 'perform' if you are drunk & you certainly wont be invited back!
Make sure you reply so that the host will know how many s/he is expecting to their swingers parties and it is good practice to call or email them just before the party date to ask if they would like you to bring anything, like a drink and food, etc. It is also wise to ask, especially if you have never been there before, for directions and where they would prefer you park.
Make sure you have plenty of time to get there on time, it really isn't good to get to the party/event late as the actio. When you do arrive make yourself known to the host(s) and have a quick tour of the house or club to get yourself aquanited with your surroundings, find out where designated areas are, where you can drink, smoke, etc. If it is your first party tell people and you'll quickly make friends and start to relax, most swingers appreciate some conversation as well as the sex!
It is fairly common place to have single females invited to parties, as female swingers especially if they are bisexual are always in demand, but it really depends on the type of party it is as to whether single guys will be. If they are and you are one of the lucky ones ensure you know what rules the host has put in place for you - are you to be 'used' in a specific capacity or is it ok for you to approach whomever you fancy?
For the right reasons! If you are going as a couple please make sure that you have talked about your own and each others expectations of the party and agree before you go what you will/wont do - are you going to stick as a couple and play together, are you going to stay in the same rooms together or are you going to split up and play apart? There is nothing worse than a couple having a disagreement when one wants to play with one couple and the other person not, it does kind of put a dampener on the evening for ALL parties concerned.
Well maybe not the morning but it is curtious to say thanks (even though you probably did on the way out) to the hosts whether it is in the swingers chat room online, via an email or on the phone. You are more likely to get a second invite if you show you have manners.