Rules for Painting
1. Clean water, and lots of it.
2, High quality brushes. This is a hobby, if you're not willing to go that extra few [insert currency here] to get a nice horsehair brush, then resign yourself to 'mucky' looking figures.
3. Patience.
4. Practice.
5. Practice.
Rules for Painting Metallics
1. <See, Rules for Painting>.
2. Once more... Yes, we are going to do layers!
AGAIN!
3. Never, under any circumstances load you brush with a lot of paint. Metallics just don't work that way. I still have the stick that I threatened you with in the yellow Tutorial. Don't make me use it...
Well then here I am again telling you numb-skulls how to paint... stuff... good... ... ...
You heard what I said!
If you've seen my 'Yellow' tutorial then you know that I'm not going to let you do anything half-arsed, so here I go!
Step One: The Base Coat
A black undercoat, check.
Brazen Brass, check.
Brushes, check.
Well then... easypeasy right? On with the Brazen Brass! No, not easypeasy. Many people will disagree with me here, they will claim that it's fine right from the pot. No, no, no, no, NO! This is
never the case, always use water with your paints, though metallic paints are the only case where this is
almost true. I prefer a nice 30:70, water to paint ratio, though others have said 20:80 works too. There is a Reason I keep telling you to thin your paints. They need it, crave it. Give it to them and they love you and are all smooth. deprive them of water and they get all stroppy, clog up and leave your lovely model all lumpy. I am firmly against dry brushing. It's fast, easy and looks like you dry bushed it. Take some time over you models damn you!
Step Two: Make it Gold
Just do the same thing again, swapping Brazen Brass for Golden Yellow
Remember 30:70, water to paint. this is because the metallic paints have a much more "watery" quality than most other paints, so not as much water is needed to make it flow.
Step Three: Make it Shine!
Burnished Gold is the lightest colour of gold that you can get and when you put it on (30:70) you're gold will now be light enough for you to call it "Gold". I never think it's enough, it just doesn't... shine. Gold needs to be highlighted. Yes! that metallic paint needs highlights, don't argue, don't winge. Sit back down and do it
Right!. 50:50 Burnished Gold and Mithril Silver works a treat (Remember to make this new mixture 30:70 water to paint as well). Do not load your brush with a lot of paint for this one, you're trying to hit the highlights, get a nice thin line; not splatter paint al over your work. Just gently pull the brush along the sharp edges and you should get a little bit of paint from the brush on the sharp corners.
Heed will these words and soon your army's trims will glitter with the best of them.
~
Nanolathe: "Fear Me! Fear the Stick!" Note: GriplionGremlin did a very nice tutorial on how to paint solid yellow, this tut is in no way meant to undermine his work. I simply do my gold a different way. I've already asked him and he said it was ok for me to do my own. So no flaming me 
you can find his tut Here