I had some pine for the drawers kicking about so I cut the back and sides, then cut channels for the drawer runner and base (6mm ply). I put a strip of ply across the front of the drawer to make things a bit easier later. It all got glued together & clamped.
I then made the runners for the drawer from some more softwood I had in the shed...I've always struggled with drawers in the past so totally over engineered em to give as little play as possible, but without being too tight.
Then I made the drawer fronts so there would be about 1mm gap around them and the face rail.