Before computers I would work on a see through paper put on top of the pattern print and then draw different suggestions to myself. I think you could do that to just get a visual feeling for how your ideas would work. This is just a pencil drawing.
Then you could put some colors on it, or even use blocks from a copy of your pattern and then play around with it in colors.
I think that EQ7 would help, but there is a learning curve there too.

Well I am glad not to pay out the $20, I shall have to research the EQ7 and see what it does and if I could do it. I think I will put it all away for now and see how I feel in the New Year when I look again, thanks for the replies.

You get what you pay for!

Margarita, I think Quilt Design wizard is a program that has a limited number of blocks available to use, in a limited number of sets. I got it for my Mom, who doesn't like computers. There aren't any very complex blocks in their library. Not sure it would do what you want!
Kathy

I have all the fabric for a quilt called Highlight and want to incorporate some dresden blocks and some split circles instead of some of the plain squares, I do have a large design wall but this is a queen size quilt and I am so stuck. Have seriously considered scanning individual components of blocks, printing them and colour photocopying to "play" with them and get it right. I just cannot "see" it on the design wall, or I have to cut all the blocks I think I will need and then find I have hacked up some gorgeous material un-necessarily. This is doing my head in, so then I looked on Amazon and see there is a thing called the Quilt Design Wizard. Would that help - I can spring for the $20 or so but the EQ7 is too expensive. Maybe there is a simple solution to this that I just don't know about. Just when I should really be making some simple quilted Christmas tree ornaments to send to my daughter in the UK this is doing my stubborn head in and I am loathe to leave it until 2013 unless I can work out what I am going to do!!