Norah, I have to agree with the Flying V Goddess. I sketch out my quilts on graph paper if I am not at home to put them into EQ5. Both of these are good ideas for finalizing your plans without cutting and regretting. I have a box of 100 colored pencils and a spiral bound graph pad I take with me whenever I feel a quilt idea coming on.
I think half the fun of making a quilt is taking the time to find exactly what pleases your eye, and letting your creativity take its time. "Let the quilt tell you what it needs" is what I have heard over and over. I spent almost a year collecting the fabrics for my "Leaving California" falling leaves quilt, and it was so worth it! Whenever I look at it, every fabric is exactly what it needed, and that makes it so much more worth the time I spent planning and sewing.
Relax and enjoy being a creative person, and don't rush yourself!
Wendy