I have some design software, can I do it myself?

Here are two things to consider: level of skill and time value.

Firstly, you may have the technical skill with software to make the items, but do you have the required ability to be able to objectively create material to represent your organization? This is more than just knowing what you want, but being able to create something that does it effectively and accurately with creative flair.

Secondly, how long would it take you? How much is your time worth? If you could do it, but it would take you two days, would you not be better off employing a designer for a few hours, allowing you to spend your time more productively on your business?

If you have unlimited time, are technically able, and have a creative streak, then you probably could do it yourself. However most people are in business to make money, not to design stuff for themselves.