So many people spend hours and days trying to design things on the computer, when they could have done it by hand in 5 or 10 minutes. If you only have half a day to do something, the biggest way to get stressed is use the computer, and chances are you won't have it done in time.
Why do they do that?
The exception is, if you have to do these sort of things on a very regular basis, then its worth learning how to create such things in a program and then when you have to do a real project, it should be dead easy.
By the same token, if you are doing something like that to gain computer experience, and you enjoy doing it, thats also good.
I have done quite a few things like that in Excel becuase I knew what I was doing and it was dead easy.