Occasionally, the subject of multi-basing comes up. I thought it might be useful to show how I do it - in case my process helps inspire someone else.
Having completed painting up a unit of 15mm Dwarves (or Dwarians) from Battle Valor Games, I first glued the figures to the bases with PVA glue. I use 40mm x 20mm or 40mm x 40mm bases, for a regimental foot print of 80mm x 40mm, though lately I've started to move towards a 120mm x 40mm foot print and a larger unit. The 80mm x 40mm regimental foot print works well for Lord and Lands and Kings of War, while the larger unit works better for Battlesystem.
The right-hand base currently only has five figures on it. The missing figure - the standard bearer - is still on the painting lid while I work on the standard.
Once the glue holding the figures had dried, I painted the bases with a PVA and water mix and then added sand for texture. While that was drying, I added some larger stones as boulders. I kept the space where the standard bearer was to go clear of sand so there would be a clean surface for the glue to grip. In the background, the unit's standard - made from standard weight printer/photocopier paper - has been added to the standard pole.
Once the sand and PVA mix had dried, I then painted the sanded base with black undercoat to seal it.
Once the undercoat had dried, I then painted the bases with my base green - Tamiya Nato Green XF-67 - and painted the "boulders" and some of the sand Games Workshop Mechanicus Standard Grey - in my Fantasy world, all stones are granite or slate.
The eagle on the Dwarian standard is a Veni Vidi Vici transfer and the patterning on the yellow border was made with a fine tipped felt-tipped pen.
Once the paint was dry, and the standard was complete, the standard bearer was glued to the base. After everything had dried, I then coated areas of the base with a PVA and water mix, and then flocked. I have two different colours of flock I use as fields do not tend to be a uniform green colour.
The completed unit. Painting on the PVA/water mix allowed me to control where the flock adhered, which allowed the boulders to pretty much emerge from the flock unscathed.
And that's pretty much it. Given the drying times of each process, I tend to paint the figures during the weekend and then work through the basing during the week - one step each evening.
Further examples are here on my Modeling Log.