Here are a few ideas:
1. Keep it to wear again to a party or formal event.
2. Treasure it - They say that prom is an event we will remember for the rest of our lives. Whether or not you will be laughing at your prom dress in 10 years, it may be the perfect item to hold onto for a keepsake. You can keep it and reminisce from time to time.
3. If possible have it shortened so that you can wear it to other occasions such as a wedding, party, dinner, etc.
4. Sell it – there are many places you can sell your dress if you no longer want to keep it.
a. Advertise on your social media pages
b. Advertise on social media marketplace pages such as Facebook
c. Advertise on other webpages such as eBay, Pre-loved, Gumtree
d. Look for local dress agencies who may sell your dress for you and give you a percentage of the sale price.