Using iconic navigation in WordPress menus means you can assign an icon for each navigation menu item you create via Appearance -> Menus admin page. The icons automatically uses your theme CSS and looks awesome with all WordPress themes. You can either choose an icon from 1400 font icon set provided by the plugin or if you already have icon(s) then you can upload it to WordPress media library and then use it for your navigation menu(s).
To start using icons in WordPress menus, first install and activate Iconic Navigation plugin. After activation visit your admin area Dashboard -> Appearance -> Menus page. Select a navigation menu and click the ‘Down Triangle‘ button on a menu structure item.
Now you have two choices, either you can click ‘Upload Icon‘ button and upload an icon from your computer’s local drive or you may click ‘Choose from font icons‘ link and select an icon from the set of 1400 icons which comes packed with this plugin. You can do this for each and every menu item, no matter if it is a custom link, page, category or whatever.
After this you can set up all assigned menu icons display for each menu location from Dashboard -> Settings -> Iconic Navigation Settings page.