Cutting fabric

I have some problems when I am cutting large pieces of fabric that need to be perfect rectangles or squares. Does anyone have any hints on how to make sure you get the perfect measurements? It always seems that I am off on one side no matter how hard I try to cut perfectly.

I was having the same problem, and I've found that by doing the following I now get perfect squares every time!  Say I want a rectangle 30x10 - First I draw two sides (ie: left and top).  Then I would measure over 10" from the left side and make a little dot, repeating every 6" or so (see picture 1).  Then I draw a line connecting the dots (see picture 2). Then I measure 30" from the top down the right side, make a dot and connect this to the left side.

  ---------                ---------   
  |          .               |          |
  |          .               |          |
  |          .               |          |
  |          .               |          |
  |          .               |          |
  |          .               |          |

  I don't know if it's the best/fastest way, but it totally works for me. I'm interested to read about what other people do!

This helped me a lot, as I am just learning.

http://jcaroline.typepad.com/jcaroline/cutting-fabric-square.html

Are you using a rotary cutter?

Thanks for the directions and the web site.
Anne, Yay for diagrams. I am definitely a visual learner.

I am using a rotary cutter and I am going to try out your suggestions Anne and will let you know how I do!!