What should I consider when looking for a VPN ?

When you look for a VPN you should take into account that normally the best VPN providers have a great catalog of features, they also offer different protocols, many servers well spread worldwide and a competitive price.
Protocols are indeed very important as they will determine the security standard of the VPN . You should look for common and strong protocols such as OpenVPN support, PPTP, IPSec, L2TP (For more detail you can go to here).
Server locations are also quite important as depending of the usage you will be doing of your VPN you might prefer to have the option to access to some specific locations.
Finally, we also recommend you prioritize VPN providers with anti-malware or anti-spy features.