Hi, first post on the forum and can't believe that I am making a foray into 6mm, but something about it that I can't explain, etc.  I'm struggling with basing and normally my method is as follows:  Glue down figure, apply coat of PVA, apply fine sand, use dropper to apply PVA water mix to get all sand soaked up and fixed, let dry, paint, flock.  

The issue is getting the PVA water mix to stop pooling with these small particle size sands I got as well as the Gale Force 9 super fine grit.  Maybe I should try a bit of dish soap?  

I found Peter's basing guide and followed it.  I cover the base with diluted PVA (about 50:50) and let it dry.  I then paint a diluted dark wash of burnt umber (dark brown) acryllic paint, which i find sticks the sand down.  Dry brush yellow ochre & then highlight drywash white.  I hope that this helps!  You can see the results on the Colin the Wargamer blog.  Cheers  Colin

I have the same method for the last thirty or so years. Reasonably thick, neat pva on base, cover with sand, leave in sand for a couple of houes or so to allow it to sink into the pva. Remove base from sand boxand leave to dry thoroughly -usually overnight- then paint. No water or pooling involved. 

I actually use the finest grain sand I can find and a coat of paint as my adhesive, that way I can control the overall color of the terrain, for good generic sand, I use a light brown.   I put a thick coat of paint on the base and submerge the base into the sand.  After letting the base stay submerged overnight, I remove the base and gently blow off the extra sand.  As a final step, I clear coat the entire base with a clear dull coat.  This projects the figures as they are handled and the keep the sand adhered to the base.

Just my input.

The dropper method as used by the model railroad fraternity usually adds wahing up liquid or meths to break the surface tension of the water.

I must admit I haven't had any problems with a 50:50 PVA:water mix paitned onto the base then the sand sprinkled on top - tip on edge to remove excess then leave to dry.  The sand I use is not super fine - just some knicked out of the kids sand pit.

as long as its not from the cats litter tray you should be fine

I find that a bag of the sand sold in supermarkets for children's sandpits provides basing sand for YEARS.