Best practices
When it comes to detecting attacks such as an ARP spoofing attack, things can become tricky. Having encryption in place for all internet traffic can help protect your session from any eavesdropping. Many browsers now require that websites support some type of encryption. There are also web extensions that can easily notify you if you are browsing a non-encrypted website. An example of such an extension is the HTTPS Everywhere extension (https://www.eff.org/https-everywhere). You will also find that modern network appliances have some sort of anti-spoofing techniques available that can, to some extent, protect against spoofing.