With our sabot basing we mount our models on steel bases from PWS (http://www.freewebs.com/pwsltd/). These can be arranged on different sizes of footprint base to represent different formations or allow us to play using units of different widths depending on playing area available. To make a footprint base we take an appropriate sized steel base (again sourced from PWS who will happily cut sizes to order) and apply some self adhesive magnetic sheeting from Magnetic displays (http://www.magneticdisplays.co.uk/).
This is a simple step by step guide which may be stating the obvious to some but I have decided to include it for completeness.
Step 1. Acquire your materials.
Step 2. As you are often doing multiple bases cut a strip of an appropriate width. Here I am doing some 60mm x 60mm bases so am cutting a strip of a sheet of self adhesive magnetic sheet 65mm wide.
Step 3. Peel off self adhesive backing and placing bases onto the adhesive surface. I tend to place a single base at a time and cut it off as it helps maximise the amount you will get from a magnetic sheet.
Step 4. Trip off the excess from around the base, and you are done!
Making these is the easy part – the difficult part is deciding what size to make your sabot elements and consequently what size footprints you will need.