There are a few rules when dealing with Cryptocurrency, like using an Escrow service. However, there is another rule of thumb you should be aware of.
If you are every looking to sell Cryptocurrencies, and need cash badly, using an exchange might not be the fastest way to get it done. You have to trade against either Bitcoin or Litecoin, and then exchange that to your local fiat currency, and then wait for the withdrawal to be processed,.... I get it, it's a long wait and you need a quick buck. But don't act like a fool...
A lot of people attempt to sell Cryptocurrency on auction sites, like Ebay, in exchange for a Paypal payment. Paypal is fast, and secure, yes. But it's also reversible, ever thought of that? You wouldn't be the first person to sell an item, in this case, some crypto coins, receive a Paypal payment & then see it reversed in the next few days.
This used to happen quite a lot with Bitcoin, where people would buy above the market price with Paypal, receive the Bitcoins (remember, Cryptocurrency transactions are NOT reversible), and then reclaim the Paypal funds because they just CAN AND GET AWAY WITH IT.
Don't get lured into these kinds of transactions, as you will most likely end up with losing out twice, both on your Cryptocurrency and your Paypal funds.