Step 1) Create a patch of lace ground pattern
Create a rectangle of lace ground pattern that is bigger than shape. For example, below I create a rectangle of rose ground that is 120mm by 120 mm.

Screenshot from Inkscape: Ground from template
Step 2) Group all of the little lines into one object
Select the entire rectangle by dragging your mouse to form a box around it. Notice there is a little bar at the bottom of the window and it shows what you have selected. In the picture below, I have selected 1536 little lines, each line is called a “path”. Each little line is surrounded by a thin black dashed box.

All lines in ground selected
We need to group all of these little lines together so that we can treat them as one object. To do this, select Object -> Group from the top menu of Inkscape.

Menu for grouping objects – keyboard shortcut is Ctrl+G
Notice that now there is just one thin black dashed box around all of the lines and the text at the bottom of the window says “Group”.

All 1536 lines are in one group
Step 3) Create the shape you want to fill
Create the shape that you want to fill in with the ground pattern. In the example below, I have drawn a star using the “Stars and polygons” tool. To learn more about drawing stars and other shapes, you can visit the following Inkscape tutorial: shapes tutorial. NOTE: If you want to create a Gimp outline or a tape outline as I did above, you need to create a second copy of your shape. You can do this using the copy and paste menus.

Create a shape such as a star
Step 4) Clip pattern to shape
Drag the shape on top of the ground pattern and position it so that the ground lines up with the shape exactly as you want it to.

Place shape on top of ground
Select both the shape and the group containing the ground pattern. Now select Object -> Clip from the top menu.

Object -> Clip -> Set menu
You will be left with just that part of the ground inside the outline as shown below.If this does not happen, there are a couple of things to check: 1) Make sure that you have grouped the ground pattern together as described in step 2. 2) Make the shape is ON TOP OF the ground pattern. If the shape is behind, you can select the shape and press the “Home” key on the keyboard. This should bring the shape to the top. 3) Make sure the shape is not grouped together with the ground pattern.

Rose ground clipped to star outline
Step 5) Outline the shape
Position the second copy of the shape around the pattern. You can use the alignment tool to help make the alignment perfect (reference on how to use the alignment tool).

Second copy of star place around clipped ground
Step 6) Create a zigzag border
Several steps are required to create the zigzag tape so I will cover this in a separate blog post (Creating a tape).
Additional notes:
For more information about clipping a pattern to a shape, try the following sources: