Over the last month, have updated a number of my sanding boards or sanding sticks.
The first is a toughened glass chopping board with two grades of abrasive paper stuck down with double-sided carpet tape.
The second example is a glass shelf with some 3M's abrasive paper - again stuck down with double-sided tape.
This is a wooden ruler with some 60 grit and 120 grit abrasive paper stuck to one side - I use it as a rough file to clean up the metal bases of models.
Finally - another glass shelf (from a medical or toiletries cabinet) with some Tamiya fine abrasive paper stuck to one side.
I prefer using these sanding boards or sanding sticks to plain abrasive paper or files as they give more control and if the sanding stick is made of wood - you can customise it to your particular needs.
I use them all (and others) on a regular basis.