Ok this may seem like a big daunting chunk of text, but I recommend you read through it, especially as a new comer to painting This is copied from my own
WIP blog on another forum, and it was some of the best advise I have ever been given, so whilst I won't take credit for it, I still think people should know it. It address's two things, the first being the best tool in a painters arsenal as far as I am concerned, a Wet Palette. The second is a more direct response to your question about wash's and should help you a tonne. There will be references in here to specifics from my own army, but the general advise can be applied for any army. Happy reading
'#1 Thing to ask about: Do you use a palette?
If yes, is it a wet palette?
If no to either of these, make a wet palette! What you'll need (and I'm typing this up for more my benefit to copy/paste later on so if you have a wet palette already, feel free to skip down):
1. A piece of tupperware, with a lid, that you don't want to use for food anymore. Clear with parents/Significant Other before commandeering one, of course.
2. Paper towels.
3. Parchment paper (wax paper will not do).
Steps:
1. Put the paper towels in the bottom of your tupperware container. Cut to size if need be. You'll want a decent thickness.
2. Add water do the paper towels until they're soaked through. You've just made a sponge of sorts. Make sure there's enough water to where the paper towels are saturated.
3. Cut some parchment paper to fit on top of the paper towels. Get four paint pots and put one at each corner to keep the paper from curling up. After a while the paper will be soaked through with water and will no longer curl. Return your paint pots to their home.
4. Ta-da! You now have one of the best tools in hobbying! Why? Let me count the ways...
Why this is awesome:
1. The biggie is that you can get more working time out of your paints. Scoop some out of a pot with your brush, transfer to the palette, and voila, that paint will be good for days. You just have to close the lid nice and tight when you're done painting (or get up to have dinner or whatever). Be sure to keep those paper towels soaked.
2. Mixing paints is more reliable. By not having to remix your paints more often (which happens a lot when highlighting and you don't want to spend tons of money on new paint pots just to use as a highlight), you have more consistent colors. Yes good.
3. I can't emphasize how awesome it is to keep paints good for days at a time.
I use masses of washes, but clearly not that well if it's not showing, I tend to use them to change the tone of a colour.
Ah. Try not to go overboard with washes. This can result in pools of wash forming on the model. When these dry, you'll wind up with unsightly rings where the wash has dried at the edges (huzzah water tension!). You can do multiple layers with washes, just wait for each application to dry. I think I notice some wash on the jump pack captain (a cool model, by the way, he looks like wrecking face is item #1 on his to-do list), notably pooling (those thick/large spots of darker color). As for changing the tone of a color...
Washes have two main uses. Contrast and Tinting. For Contrast, use a wash without diluting it. You can use an undiluted wash over a large area or painting between raised detail (like the ribs on Mephiston's chestplate, or between fingers wrapped around a weapon, or the place where a hand meets the grip of a bolt gun). Some tricks to using a wash undilted: you need to be careful to prevent pooling. This can be averted The direction of your brush strokes will have a huge impact on the effect. Remember to start your brush strokes where you want the least amount of wash to be, and end it where you want the most. One the painting between detail, try this: look at the arm of a regular Tactical marine. Notice those little crevasses on the forearm? When you have the arm painted up as you main color, say Blood Red, get a bit of wash, Devlan Mud perhaps, on your brush (a standard will do the trick for this), make sure it isn't dripping (a whole other paragraph), and then "paint" the wash into that crevasse. Looks pretty good, right? This is known as "black lining", because the original technique was to use thinned black paint to increase the contrast between areas of two different color (between fingers, where a hand grips a weapon, if the shoulderpad is a different color than the trim, etc).
To tint, dilute your wash. How much depends on how many layers you want to do. Play around, experiment with a piece of sprue primed and painted in a light color. Get a feel for what effect the different colors bring. For example, parchment and purity seals. Sepia works great for this, but a diluted 50/50 to 75/25 mix of Sepia and Devlan Mud is a different look, subtely, and looks wonderful.
Okay, I think that'll do on washes for now. If anything was confusing, let me know! Ask questions, experiment with the paints and washes and take pictures and let's talk about them!'