Each browser allows you to disable cache of your webpage, ensuring your resources come from the server each and every time.
In Chrome, you'll find the option in the settings cog.
In Internet Explorer, the option is under "Cache" in the menu bar.
In Opera, to clear the cache click the Network tab, select the Network Options secondary tab and choose the first option.
In Safari, you can disable your browser cache under the Develop menu in the menu bar.
In Firebug, you can disable your browser cache under the menu in the Net tab.
To bring up the clear cache (and other data) dialog on any browser press Ctrl, Shift and Delete in Windows, and press Shift, Cmd and Backspace on Mac.