The more different layers that you apply; the more the cloak will come to life. If you only apply three colors (Dark Angels Green, Snot Green and a Highlight of Skull White) you will find that the cloak looses depth.
I would suggest the following:
1. Since you have already base coated with Dark Angels Green, I would now wash the deepest parts of the cloak with a Chestnut Ink or Dark Green Ink wash. Use a fine brush and a thinned down Ink wash, only applied to the deepest parts of the cloak.
2. Decide which areas are higher (or lighter) than the rest and cover about 75% (except the deepest parts) of the cloak with a watered down mixture of Dark Angels Green and Snot Green. Don't be too worried if you can barely see the color applied. THIS IS GOOD.
3. Repeat step 2, but only cover about 50% (taking care to show places where you can see your effort in step 1 and 2), with a watered down mixture of Snot Green.
4. Repeat step 3, but only cover about 25% (taking care to show places where you can see your effort in step 1, 2 and 3), with a watered down mixture of Snot Green and Goblin Green (I forget the color ranges, but this should be the lightest green that you can find).
5. Repeat step 4, but only cover about 5% (taking care to show places where you can see your effort in step 1, 2, 3 and 4), with a dry brush of pure Goblin Green. This should be the very highest parts of the cloak, or the edges. Make sure that you don't put too much paint on at this step. Little is better than too much!
6. Lastly, cover about 1% of the cloak with a fine line or two of a mixture of skull white (85%) and goblin green (15%). This should be the finest of lines or the smallest of areas! Remember, LITTLE is BETTER!
Then your cloak should be done...
If you keep the paint watered down, you will find that the paint gradually builds up to the lightest colors. The idea is to build up layers, and not to see a difference in one layer of paint. If you take a bit of care and a couple of hours, it would make the World’s difference in the end effect. Remember, you will only notice your efforts, and that it paid off when you apply the last step. Keep at it, and keep faith and HAVE A GOOD SET OF VERY FINE BRUSHES HANDY!