Step1 Set up account with Craigslist.com in your area. Look at listings for similar gift cards and get an idea of the price. Use search term "gift card" in quotes. Most will be about 70% of face value of gift card. Some gift cards will be as low as 50% of face value.
Step2 List your item and don't worry about adding a picture. Price your card to market value. Make sure to include that all sales are cash only. Use your phone number for quicker sales.
Step3 After listing your card, check your email frequently. Sales will be lost if you are not responding quickly enough to email requests. Using the phone is quicker and you can leave message and return calls.
Step4 Meet with buyer at the store. With use of cell phone it should be easy to arrange meeting and direct to exact location. Expect to deal in cash. Make sure buyer knows this up front. Do you know how to spot forged money? Most people are honest but it doesn't hurt to learn about money.
Step5 While buyer is watching, check validity of card with store clerk. The buyer can then pay you and have the card reissued. Buyers should always be in the habit of having card reissued.
Step6 Buyers should get ID from the seller to protect in case of fraud. There are some cards that have a higher theft resell rate such as American Express. Take the precaution and ask to record seller information from picture ID.
Step7 Sellers, after leaving the store make sure to set voice-mail messages with a greeting indicating the card is sold. Then let all unknown calls revert to voice mail. Make sure to end your listing with Craigslist or Ebay.