If it is short term and you want to sell something quickly like now then classifieds is your best option. But if you are going to be selling for a long time then selling your services on your own self hosted website is probably the best option for you. You can then drive traffic to your website via social media such as Facebook, twitter, google plus.
The major advantage of selling on your website is that it's your platform is that you own it and you can experiment and play around it in any way to achieve the maximum benefit. You can also then add an ecommerce operation to enable online payments and so on.