From my  little experience, I'd say that ForkDelta has been quite safer than EtherDelta in recent times.

Safest options are:

I. Have your metamask extension installed. Mind you, the metamask extension is now available even for mobile devices on browsers like Yandex and Firefox...
II. Withdraw your eth or coins back into your wallet after successful trade
III. Never forget to click on "forget"... Simply put, always log out before exiting the browser

With these in mind, the risks involved are greatly reduced.

Cheers!