First you will need to come up with a theme for the Valentine's Day dance party. You can pick the type of music and the decorations for the venue to go with the theme you choose. If you are into classic and old school dancing, you can take inspiration from period movies like the Great Gatsby, which has some really colorful sets and some amazing music.
You also need to ask all the guests to dress according to the theme and if possible, even choose costumes or dress up as popular figures or characters from movies etc. For instance, your guests can show up as Cleopatra, Romeo and Juliet or Beauty and the Beast. Costumes will add personality to your party and will guarantee a fun evening.
If you have a limited number of guests you can pick a hall in your home or arrange the party at a friend's place if there is space. A wide backyard can be ideal for custom decoration and lighting. On the other hand, if you can afford it, booking a club hall can also be a great idea.
No party is complete without food and drinks. Allot a refreshment area with proper arrangements for Valentine themed treats. You can fill candy bowls or martini glasses with candy hearts along with different drinks. You can also make sure there are enough seats for everyone to sit down comfortably and chat.
You can also book a professional photographer for the event, whose job is to make sure every guest is properly photographed and there are plenty of photos of the dance floor. These photos are going to be mementos of the amazing evening and everyone will want to get their hands on them after the party.
Make sure that your guests can easily find cabs on their way back and you should also help get cabs for guests who are unaccompanied and have had too much to drink. Since it is your party, you are also partly responsible for the safety and well being of your guests.