I got tired of the squared-off bases where I could see the seams of the walls/floor junction when printed, so I made one with a 1mm radius to soften the corner and hide the seam. It is 3mm thick (nominal) at 25mm scale (I like a 26.5mm base) but can (and should) be scaled to 4mm if using for larger (50x50, 75x75, etc) bases for larger creatures.