I am used to doing this in Windows with FireFox or IE by pressing
Ctrl + F5.
Is there a way to do this for Safari on a Mac?
Go to Safari>Empty Cache, or Opt+Cmd+E. To refresh, click the refresh button on the addressbar or press Cmd+R.
Another tip. If you want to restore Safari, like completely clear all the caches, or parts of it, go to Safari>Reset Safari. I use it usually when I need to clear a lot of memory from Safari, for it will clear the webpage screenshots, the cookies, the favicons, etc.
Shift and clicking the Refresh button generally does a full refresh. You can also empty cache with option command E, and then refresh.