This filament spool holder is very simple, but effective.  It is moveable so you can slide it along the 1x2 piece of wood with ease.  Three M3x10 screws in the back provide for a tough grip on the wood to hold the part in its place.  the angular force from the filament causes the screws to press into the back of the wood and therefore hold it where you put it.  Take note that this model does not require screws to be placed into the wood, just into holes that are already in the plastic model.  This model should be printed with high infill so that the part will not flex and lose grip on the wood.