Never, never turn down a party invitation. Whether it be a friends, a beach party, office party, etc. Parties are a real gold mine for meeting women. The atmosphere is very sociable and conducive for flirtations.
All you've got to do is walk up to a woman you're interested in and introduce yourself. Then follow up with your conversational skills.
Also, it's a good idea to throw your own party. Invite everyone you can think of. For instance, if it's a male friend you invite, ask him to invite some of his female friends. If it's a female friend, ask her to invite some of her female friends. This way your party will be stocked with an ample supply of women. This will give you an opportunity to meet some new women and make friends.
When at a party, whatever you do, don't stand in a corner. Be sure to mingle and flirt with as many women as possible. There's nothing to fear because people will be friendly and rejections are rare unless you make a fool of yourself.