Open Google SketchUp and create a 3D model of your future feeder. Specify dimensions and make corrections when necessary. Print it out on paper.
Buy a ready-made spruce board at your local building center, go to your workshop, and start building your feeder.
Outline parts according to your blueprint. Mark out and specify all dimensions on the board (leave a 15-20 mm margin) and cut it into rough pieces.
Step 1: Do the Final Sawing
Do the final sawing.
Once all parts are finished, mark out faces and edges.
Cut rabbets as specified in the drawing. The rabbets will help you position parts and facilitate assembly.
Step 2: Mark Out and Cut Out Windows
Mark out and cut out windows.
Now you can start fitting it up. Trim the parts if necessary.
Step 3: Sand the Parts
Sand the parts with an 80-grit and then with a 120-grit disc.
Round edges where necessary using a disc sander.