I mainly use three materials, fine ballast from Woodland Scenics, coffee grounds (the same as the mid-level texture on my terrain boards), and static grass - usually from Games Workshop because that is what is always available locally. Of course there can be more details, but this is the basis for almost every model in my collection.
When making units, I try to keep in mind where the bases will join those of their comrades to get as seamless appearance as possible. I apply white glue directly to the base and spread it around with a damp brush. I use the base as a pallett initially. just getting a small amount on my brush and carefully applying glue around the feet of the models before thinning out the rest.
I have two tubs of basing material. The initial dunking is in the coffee grounds, and I just dip in a corner or two, or else pick up a pinch with my fingers to sprinkle a trail down the center. Then the lads are placed in the fine ballast and the extra shaken away. I use my finger to brush away any stray bits on the edges so I can line them up properly on the table.
I let this dry, normally over night, and then add paint directly on the texture, taking advantage of the natural color of the materials as my base. I use Wargames Foundry Base Sand A and use sort of a heavy dry brushing technique. Then I pick out out some of the larger chunks with Wargames Foundry Slate Gray A and highlight with Slate Gray B.
WHen the paint is dry, it's back to the glue. I only put one dot on the base of a single model and maybe two on a larger stand. A little goes a long way with this step and I want my earth to show through. I use a damp brush to randomly push the glue around and skip around to the base to make small tufts. Then they go into the third tub...
That's it! Sometimes I might add larger tufts of grass or stones, bits of fencing, discarded weapons, etc, but for the most part I try to keep things simple. I have more models to paint and I don't have time to hand paint mushrooms and the like. This style also matches my terrain boards well.
Hopefully this was helpful! I keep meaning to do more in the way of hobby articles rather than just 'look at the new thing I painted', but life has been stupid busy of late. In any case, the next time someone asks me about basing I will be able to find the article!
I await the comments on TMP has to how the 74th never fought an a battlefield with the sort of stones depicted on these bases...