This is my process to make a sketchbook with simple materials and tools you may certainly have at home. A nice feature of this notebook is that it can lay flat on a table and its covers are wrapped in cloth.
Step 1: Folding and cutting
Gather coloured sheets of paper (A4 size) and fold once. When pressing, use a blunt object, e.g. a fork, to obtain neat folded edges. I have folded 4 sets or sections of A4 sheets (each set has 4 folded sheets). When you have folded all sets, cut in half using a knife. The final sketchbook will be approximately 10cm x 14cm (almost A6 size, 4×6in), after trimming the edges.
Step 2: Making the holes
Using a pushpin, puncture the inner side of the folded sets. There should be an even number of holes. In this case, given the size of the notebook, there will be four holes.
Use one inner sheet with four holes as a template to finish the other sets. You will get aligned holes.
Step 3: Sewing
When all holes are ready, grab the first set of folded sheets and start sewing into the inside of the sets. Start from any hole that is near the edge. Use a regular sewing thread. Join the sections together at both ends with knots.
Step 4: Gluing
Once all the sets are sewn, we need to glue a piece of cloth. This will keep the sections fastened together, specially when the book is opened between the sets.
Find a regular piece of cloth, from a discarded shirt for example. It should cover the back of the sections and extend around 1.5cm (0.6in) around the first and last page (Please see last photo of the set).
Apply adhesive to the back of the sets and half an inch on the first and last page of the notebook, then attach the piece of cloth. Finally make sure the piece is glued to the sheet and trim any excess.