Basing Figures.
Here's what I use for the first stages of figure basing. The main ingredient is Basetex which is an acrylic basing medium made by Colour Party that combines paint, glue and texture into one easy-to-apply paste. I buy mine from either Colour Party or one of their stockists. Basetex comes in a variety of colours and sizes. I mainly use BT27 Dried Earth which is the one pictured above. BT19 Green Basetex is very useful as well. I buy my Basetex in 500ml tubs for £10.00, but if you want to experiment first it's available in 100ml pots for £2.25. Basetex is very heavy so the postage is expensive at 50%. Try to get some at a show if you can.
I use a small palette knife to apply the Basetex and a piece of brass wire to push it into small spaces. The cocktail sticks are in case of very small spaces. It's a good idea to have some kitchen roll handy to wipe your tools clean and fix mistakes. Should you get some Basetex where you don't want it, a liberal application of clean water with an old paintbrush will flush it away.
The jar of grit is for later.
Basetex is thick and can be thinned with water, but this doesn't affect the application process. I work from the centre out so that I can keep a good, firm hold of the base whilst poking the Basetex into the complicated areas between the figures and still keep my fingers clean. Once this difficult part is done I can hold the group by a figure and finish adding the Basetex to the outside.
I always do the basing of an army in one go once I have finished painting it. A good base can make an extraordianry difference to the way a figure or element looks. I really do believe that even with a very mediocre paint job, spending a bit of effort on the shields and bases can improve the look significantly. Conversely, a superb paint job can be spoiled by sloppy basing.
I tend to use Basetex, produced by Standard paints for most of my basing. I don't know who retails it I am afraid, I usually pick up a jar when I go to Wargames shows, and never take note of which stand I bought it from! It is esentially a water based paint with grit in it - I guess I could probably make my own, but at around£2 a jar, it's just not worth the effort.
I use 2mm thick plasicard for my bases. I have never had a problem with warping or splitting, and it is easy to cut.
Before the figures get stuck onto the base I score the surface, this is to make sure that whatever I am going to stick on there - Basetex or whatever - has something to grip to. I have never tried it without scoring first, but I suspect the surface would be too smooth. I also paint in the edges of the base at this stage, it makes the whole thing look so much tidier when its finished.
Once that is done, I slap big dollops of basetex around the figures using an old tatty brush to work it up to, and onto the figure bases. I use enough to fill the gaps, and even out the overall surface, using a stippling motion to retain the grainy texture. Once that's done, leave it to dry out completely. This will ruin a decent brush, so make sure you use one you don't care about. Stiffer bristles are better.
When it is dry, as in the top left picture, I then dry brush the whole lot with a colour a couple of tones lighter than the Basetex, as shown top right. I then follow up with another dryer dry brushing using a lighter tone. This really accentuates the texture of the base (bottom left). The last stage is the static grass. I put irregular patches of slightly diluted PVA glue on the base - usually including the area around the figure's feet, then scatter the whole lot with static grass. Give the glue long enough to dry - about 10 minutes or so - then tap the excess grass off. A final blow to get the last of the loose stuff off, and there you have it one element totally finished.
Further basetexing tips:
http://28mmheaven.blogspot.co.uk/2011/09/28mm-vietnam-project-part-5-basing.html
http://www.matakishi.com/pspainting.htm
http://barbariansbearsandbeavers.blogspot.co.uk/2010/09/artillery-redoubt.html