Carcearion:
Alright, so I have gotten allot of positive feedback on my basing so I thought why not go through and make a tutorial. To start with I’d like to say that you can get an equally good (if somewhat more subtle) effect with GW’s cracked earth basing product, it’s a great effect �?" however it is super expensive if you are going to be doing allot of large multi-bases, terrain pieces, or are planning to do a whole game-board it would cost a fortune (literally like hundreds of dollars to do a game board!). So if your looking for either a way to cut down costs on your army or for a way to do something larger then GW pot prices allow I think this is the way to go
What You Will Need:
1. Tube of Kroma Crackle Medium (Which should be easy to find online or an art supply stores, I got mine at Blick)
2. Any old earth tone paint you like
3. Hobby Knife
4. Course Sandpaper
5. Games Workshop None-Gloss Wash Paint (I use Nulin Oil and Seraphim Sepia)
Step One:
Scratch up your base with the hobby knife and then sand it a bit with some course sand paper to rough up the base
Step Two:
Base coat in black. Do this step even if your using a black base as the paint helps the crackle medium adhere.
Step Three:
Apply any bits to the base which are supposed to appear embedded into the earth. I recommend sanding down some of the bits heavily to improve the illusion of them being buried.
Step Four:
Base coat said bits, make sure to clean up the surrounding base with black again.
Step Five:
Mix a very small amount of your earth tone paint (I don’t have much of a measurement here, I typically just use my standard brush as a scoop to measure out about 4 �?obrushes of paint") per 1/2 Table Spoon of the Kroma Crackle. Stir well until the crackle medium is colored.
I use a 50/50 mix of Tallern Sand and Ushabi Bone, but I actually recommend using something cheaper then GW paint.
I cannot stress enough that you want to use a very small amount of paint, you want to be sure 5% or less of your mix is paint or it will not crackle. It only takes a tiny bit of paint to color the crackle medium.
before mix
after mix
Step Six:
Coat the base generously with the mixture, you want it to be at least 1mm thick. The amount I sited above coats this 50mm by 100mm base very well, but doing anything larger you will probably need to mix more. If you have just one or two spots where the black shows through it shouldn’t be a problem, the mixture will level out.
Step Seven:
Place the mixture some where safe from tampering and let sit for 1 to 3… DAYS!
This is the biggest downside to the Kroma Crackle it takes a long time to set. How long it takes will depend on the humidity and temperature, if your hobby space is a little damp and cold (like mine) then expect it to take the full three days, if you make the mistake of placing it in a very cold and damp place (like I did once) it can take almost two weeks! This process can be sped up by putting it under a desk lamp. The most difficult part of this step is resisting the urge to poke it and see if its done 
When it initially stars to harden it will look very dark, but as you can see it will lighten as it begins to fully dry
completely dry base
Step Eight:
Once the crackle is set do a wash over the entire base and all of your bits. I use a mixture of one part Badab Black, one part Seraph Sepia, and one and half parts Water. In this instance I really do recommend the GW washes.
For doing really big bases this can be time consuming and use up allot of wash, also you may see streaks and lines as you wash the big basically flat surface don’t mind these once the wash dries it brakes up these brush strokes and will just become more texture. If your doing a very-very large terrain piece or a whole game board I would recommend formulating your own wash.
the fully dried wash
NOTE: I did not take a photo of the undried washed base, it can sometimes take a long time for the wash to totally settle in and I think actually absorb a little bit into the crackle medium, it may look unusual and too dark until it fully dries I recommend letting it sit overnight.
Step Nine:
Highlight the bits you stuck on. I use a simple dry brush of the original color. If you have skull eye sockets or similar area’s which should be dark I’d recommend putting in a drop of black wash. For more contrast on the skulls I sometimes like to mix in a bit of white to the original color and do a lighter second dry brush as well.
NOTE: This has actually already been done in the photo above
Step Ten:
Stick on brush or other objects not meant to be embedded in the earth. For best effect with brush have some it cluster around embedded objects as though they grew in their shadow.
Step Eleven:
Put on dudes! Your done 
This Crackle medium is very versatile stuff, you could easily follow these same steps to make lava bases if you simply base coated in a swirl of yellow, orange, and red and then used black or another very dark color for the crackle mix (or just as easily a toxic base if you base coated the base in a bright venomous green or purple). If your doing a bright base color you want to show through the crackle skip the wash step and instead dry brush the crackle the original dark color
:hat off