Making a supplemental living or going pro with freelancing online requires a specific skill set–and a toolbox containing all manner of special tricks and techniques. Building your toolbox while refining your skills comprise a fair amount of the work involved in creating a freelancing career, and one of the most important items in your toolbox is your portfolio. A great freelance portfolio should highlight your talents and give potential clients a meaningful way to choose you amongst your competitors–something that can be especially critical during your first few months, but which will remain important as you develop your reputation and experience.