Hey all,
First time poster long time lurker so go easy on me. I have made a couple of models before and am slowly picking up my array of tricks and skills yet am no where near good. These are a couple of them: 
and http://i.imgur.com/2uh4s.jpg Well, I have a couple of questions for you in that case. Here goes.
I am working on the Timaya M2 Bradley Tank (well just starting) and feel a bit scared to get into it. What I want to do is create a texture on it before I get too far into it and realize I did not do enough. I must point out that I do not own an airbrush and realize this may be a big problem. I am not against buying one in the least bit, I just do not have the finances at the moment to pursue this as of yet. I have a few ideas as of right now and would like your criticisms and input as to how these work. Of course I will still being doing them on scrap plastic to see how they work (for science!) and for my future knowledge. Here are my ideas:
a) Spray a thick coat of primer and sprinkle sand. If the sand sticks to the primer, spray another coat and let dry then follow up with my final spray color.
b) Use spray glue and stick the sand on that way. From there, spray a coat of primer to ensure my final coat sticks to the model.
Of course I don't know if either of these are going to work but what is the harm in experimenting. I also have another question. How important is primer? I just use it because of my background in carpentry and painting walls but I don't actually know how well it works or if it does things in certain situations so I am looking for some information on that.
To end off I will try to put what I am saying in a simple a way as possible as this may be a bit confusing.
I am trying to create a texture as if someone was on an assembly line trying to push out as many tanks as possible in a short time with little care for blotching or clumpy paint. I have heard of using talcam powder but I think that was only with an airbrush. Thank you for your help in advance