I'm coming at this from a beginners perspective, I even got my partner to make one.
This is my first instructable, and I'm pretty new to making anything, so comments and suggestions are more then welcome.
Step 1: You Will Need...
Sewing machine/ needle and thread- I did mine by hand.
Tailors chalk/ Pen/ Pencil
Step 2: Cut Your Fabric
Pin your template to your fabric so that it won't move and cut carefully around the edges.
You will need 6 squares per block, I made 6 blocks so had to cut 36 squares of fabric. As I had 6 different fabrics this was 6 pieces from each. I cut a couple extra from each to give me so flexibility in the patterns of the blocks.
You should end up with lots of squares.
Step 3: Making the Block
As you can see I embroidered five squares to spell out a name, you may wish to add shaped patches, letters, or similar. One of these embroidered squares will form part of each block.
I advise you to lay out each block that you want to make, that way you can see the pattern and cut any additional squares out at this stage.
Give each square an iron to remove any creases.
Step 4: Draw on the Seem Allowance.
Turn your fabric over to the back.
On each square measure out your seem allowance, basically I drew a 10x10cm square within the square. Be careful what you use to draw your lines as you don't want it showing on the good side.
Continue to sew in the other squares until you have a cross shape. See the photo for reference.
I found that creating this shape first helped ensure that all squares were stitched to the correct square at later stages.
Step 6: Make the Corners.
When looking at how to write up instructables, I found this page which really helps describe the process of turning the shape into a cube.
From the shape in the previous step, fold it up into a cube allowing you to visualise which sides need to be stitched to which.
Stitch the block inside out, folding up the sides, pinning and stitching along your lines.
Be careful not to sew onto other squares, this gets trickier as you complete the block. Make sure you fold back all squares our of the way.
When stitching from one square to the next, make sure your corners meet, I found it easiest to form a continuous stitch where possible.
Make sure you keep inside out.
Step 7: On the Last Side
On the last side, leave a gap un-stiched, in my blocks case 3-4 cm.
Trim off the corners, making sure not to cut the stitches. This will make it less bulky.
Turn inside out (or, I guess right way out)
Poke into corners gently with the knitting needle to help make corners.
Stuff with toy stuffing.
Hand sew up remaining hole.
Tadaaa you've made baby blocks!