Polishing Compund Bars

When using polishing bars such as tripoli, white rouge, etc...what's the best way to get the compound onto the buff? It sounds to me like it would be self explanitory, but it seems like the compound is difficult to get on the buff!
Maybe I'm a complete moron, but if you know something I don't please post!

[1BADYFZ]

just grind a little on the bar to get some compound on your cutting wheel, then start cutting the aluminum until it starts to leave heavy scratches, then reapply more compound.