Need pointers on creating more realistic tank textures Thread

I'm in the midst of creating a vehicle (more specifically, a Tank) in Maya for a Uni project, it needs to be skinned and I'd like to do it from scratch without pinching bits from other 'professional' texture maps like I usually do to save time when working on the Eastern Front mod. I have about 5-6 years experience in Photoshop but my Artistic skills in the programme are sub-par (even with a tablet), I tend to lose my patience after spending hours and hours slaving over a texture trying and get it looking realistic but my textures always come out looking like absolute crap.

So I was looking for some pointers on what I can do to make my textures more realistic, in a quick and effective way if possible (since the deadline for this project is the 9th of May) and specifically how I can get paint effects, welds, dirt and scratches looking realistic without going over the top. All I really want is to do is get a realistic looking painted base down that I can build on. Any tutorials, decent brushes or advice people could throw my way would be awesome.

Thanks!

This tutorial has served me well in the past, and includes a nice brush or two:
Moddb.com
You may also want to look at Forums.cgsociety.org and Cg.tutsplus.com

These all it makes for some fine bases (you can tone it down if needed).

Oh man, exactly what I was looking for, thank you very much!

First off, you don't "paint" realistic textures - not even the artists at Blizzard are that good.
You create realistic textures by photo-manipulation of either stock/base textures or your own photographs.

First you get a base texture, from like www.cgtextures.com
Then you alter that texture quite heavily with adjustment layers, blend mode layers (ie: layers that have other blend modes than "normal") your own strokes, grunge and dirt brushes, text, masks and so on.

Also, without an Ambient occlusion, specular and normal map you can forget about making it realistic. Set the blend mode on the AO to "multiply" and have it at the top of your layer stack. The specular you can create from the diffuse map - but don't just desaturate it, increase the contrast and "think" that that's a good way to make a specular map.

If you have lights on the tank then I also suggest that you use an emissive map for self-illumination. Export everything as OBJ and TGA's - and import them to something like the Marmoset engine.

This is just my workflow. There is no way I can tell you have to make great textures with just a single post here you need to study tutorials for that and learn the features of photoshop better.
Before I got into game development, I had used photoshop for about 5 years as well. And all I can say about those years is that i knew NOTHING. It's not until about now that I honestly can say that I do know everything about photoshop - or at least 99% of it. And that took a while.

EDIT:
Photoshop brushes is a good start. Every artist need them! I use both my own and other's work when I do textures.
Browse.deviantart.com deviantart search for photoshop brushes
Niteshader.deviantart.com - my grunge brushes (don't mind the preview image, it's crap and I made it in 2 minutes)

Edited by: Nightshade

I think you misread my post. I'm not looking to 'paint' realistic textures, I'm looking to make realistic 'paint' textures... a good looking texture base on which I can build on. I already know all about occlusion, specular, normals, etc etc, these are a normal part of my work, I just needed some pointers to help me speed up the initial process. I have this now, Cryid's post helped immensely.