[Q]: Objective: To clean dust out of your keyboard,
[A]: use a can of compressed air to blow the dust out of the keyboard.

[Q]: Objective: How to finish piece of wood for shelf.
[A]: Coat wood with teak oil to seal it.

[Q]: Objective: Draw a large circle on a large piece of fabric.
[A]: Place a round waste basket on the fabric and draw a circle around the bottom onto the fabric.

[Q]: Objective: How to made shield edges smooth.
[A]:
Using sand paper, rub the paper along the edges of the shield until all edges are smooth and not sharp.