Great question! I want to know too!

You can start simple, by digitising a fill at a low density and copying and pasting 3 or 4 times.
In the case of 3 set the fill angles at 0, 60 and 120 degrees. Use a low density (I use 25 or so in Embird) and no underlay.
When you use 4 layers there's a bit of arithmetic involved as the diagonals are the square root of 2(=1.4) longer than the straight sides, so densities could be 30 and 42.
Add some nice satin stitch lines to create a design.

And you can make it a bit harder on yourself by making your own motif fill (use User Editors). The picture shows a variation on motif 9, I doubled the stitching line to give it some body. You see the pulled down top line - that's to make sure the stitches overlap. One layer will do. You can make the most wonderful fillings that way. You could use that for certain areas of your FSL. see picture 2.

Make sure you make connection stitches - nothing as disgusting as having jumps in FSL.

Have fun experimenting.

Dianes Designs sell tutorials on digitzing lace.
The tutorials are offered for many different brands of software.
Click on the different Software names on her site and there will be all the tutorials for that specific software.

She also has some basic lessons on her Yahoo Group.
You can ask questions on the group and she will answer your questions.

Hope this helps you!
EastWitch2

Link to her Tutorials and her Yahoo Group below.

Here is Dianes Website.
Click on Digitizing Tutorial CDs and Videos then click on the different brands of software to see all the Tutorials for Lace etc.

Sorry forgot the link to Dianes Website Home page.

Link to Dianes Website.
click on Digitzing tutorial CDs & Videos on the home page then click on the specific brand software to see all the Tutorials for it.

EastWitch2