You will need: wood glue, wood dowels, wood drill bit and a hand drill.
This is an excellent joining method, because it is invisible and very strong, ideal for thick or even very thick plank furniture.
The tricky part is drilling the holes - it is important to take your time.
The wood drill bit must have the same diameter as the dowels: for example 1/4 inch (about 6 mm).
To make the task easier, lay your dowel locations before drilling. To do this, make a guide out of a piece of cardboard.
On this cardboard, draw and cut out two circles to represent the dowels. Place the guide over your wood and trace the circles with a marker.
Measure the length of the dowel then divide by two. To avoid drilling too deep, mark this "half-length" on your wood drill bit with a rubber band.
(Certain wood drill bits are pre-marked.)
Now position your drill bit in the center of the traced circles. Before drilling, drive the tip of the bit into the wood.
If the tip of your drill bit is not sharp, then it is not a wood drill bit.
If you are using an electric drill, begin with the lowest speed and then accelerate gradually.
Stop drilling when you reach the rubber band. Turn the board upside down to empty the sawdust. Repeat this procedure for the second hole.
When all the pieces of wood to be joined have been drilled, squeeze a little glue into each hole,
then insert the dowels and assemble the wood pieces. Assemble the top board last.
Check that the assembly is perfectly straight, place some weights on top and let stand overnight.