|If you have Photoshop or Photoshop Elements, you can take a photo of your fabric and combine it with the line drawing of your pattern.
To do this, open your photo of the fabric in photoshop. This can also be a copy of an online fabric swatch instead of a photo of fabric you already own. Make it an appropriate size, which will usually mean downsizing it (you don't want the fabric texture/design to be huge on your line drawing).
Then select a square of the photo (where the lighting is even) or the swatch, go to the edit menu and select 'define pattern'. This will make your fabric appear as a pattern in the paint bucket pattern collection.
Now open your line drawing in photoshop, click on paint bucket, select pattern in the fill field, select your fabric and 'paint bucket' your line drawing.
You could also have a photo of yourself and the people you sew for, and combine it with these simulations in photoshop. Kind of like the paper dressing dolls we used to play with as children :-)