How do you throw a perfect cocktail party?

Work out what cocktails you are going to make beforehand. Have a variety of cocktails but limit to a mangable number. Do not make them up as you go along (except at the end of the night when everyone is drunk and it seems like fun). Try making the cocktails a few nights before to get the mixes right (doing this on the afternoon of the party may not be a good idea...)

Make sure that you have all of the ingredients (including ice!) and equipment prepared (chilled or frozen if necessary) before guests arrive. Have plenty of glasses so that you not constantly washing up.

Have appropriate music selected and playing when guests arrive.

Serve food and water/soft drinks.

Avoid cocktails with cream. They are usually disgusting.