Do you thin your paint with water at all (not to the point of making it into a wash)? If so, then how much water do you add?
Definitely do, paint straight from the pot is usually so thick it obscures detail on models and several thin layers takes longer but looks much better than one thick layer. It is hard to describe the required consistency, you need to just play around with some paint and water until you find something you are happy with. You don't want it to be thin enough to be beading up, or showing too much of whatever colour is under it, but you also don't want it to feel thick and dry. In addition to the benefits to your models, it also helps your paint brushes last longer to always be wet and not have paint dry in them.
Thinning is definitely a must! What I recommend is using a White Undercoat, then thinning your paints almost to a wash like consistency. Then when you apply it to the undercoat, it adds natural shading, reducing the amount of work you have to do. You then slaver on Ogryn Flesh, leave to dry, and highlight with and appropriate colour. BINGO, Instant gorgeous model!
Yeah I pretty much always water down my paints. Sometimes I find the consistency out of the pot is good enough for speed painting, but even then I always put the paint on my palette instead of going straight from the pot, so I need to water it down a bit to stop it drying on the palette. Most of the current range of GW washes I use straight from the pot though, they've actually gotten the consistency of washes really good for most uses.
Hrmmm...guess I ought to start trying it then. I've painted a few skinks (just as color tests -- I'll put them up here soon-ish), but I didn't think to thin the paint any. The only time I watered them down any was to create a wash. So what's the best way to do it? Syringe? Eye-dropper? Brush in the water pot?
I just dip the brush in my water pot and then use the brush to mix it into the paint on my palette. If I need a lot more paint on my palette than the size of the brush I'm using (speed painting or perhaps fine detail work) I have a few crappy size 1 or 2 brushes with the tips cut off them for the sole purpose of extracting from the pot, watering and mixing paints together. Because they're crappy brushes I just leave them in the water while I paint as I'm not afraid of damaging them further. I started doing this when I realised a large portion of my painting time was being consumed simply taking paint out of the pot, playing around to get the right consistency, mixing paints together and cleaning my brush often from it getting dirty quickly while performing the above tasks. Having the tip cut off means it can pick up and hold a lot more paint and water. Also remember GW paint pots are terrible, the paints dry out so how much water you need is always changing, and occasionally you need to drop a few drops of water directly into the pot to help slow this process. Funny thing, when I was looking for some liche purple to paint my skinks, I found 2 pots of dried liche purple paint and 1 working pot of paint... the working pot was from some 13-15 years ago when GW actually made paint/pots that didn't dry out.
There is no 'right' or 'wrong' way. First, always thin your paints down. The only exception maybe if your going to drybrush. The amount of water you use strongly depends on what you are painting and what you're trying to achieve. It is always better to use several thin layers then one thick. Of course for some parts the paint should not be thinned down to much (like for eyes...) whereas for other parts the paint can be thinned down pretty much (such as basecoats, ...). Most of the times people call the consistency 'like milk'. Now, how to thin is up to you. Some painters even thin their paints directly within their pots. You can use a dropper (like empty vallejo bottle or even bigger from your hobby store) or the take the water directly with a brush. Using a dropper is sometimes very handy if you are using droppers for your colors also, therefor you can get 'exact' ratio of water and paint. But the brush also works well. Personally I use both, I have a big plastic dropper with distilled water but I do not use it all the times. Sometimes you want to use distilled water because in some regions the water from the tap can be very 'hard'. This can increase the tendency of your colors to separate. Also there are several other mediums you can use for thinning down your paints, like glaze mediums, thinners, alcohol, etc... but I think should first try to work with paints thinned with water. best, G.