DRAWING AND PAINT

Next grab your number 2 size brush and add some thinner lines at the ends of your branches.

By now you should have a nicely constructed base for your leaves as shown in the picture to the left.

Don't forget to add the shape at the base of your tree at this stage... see how the very bottom edge of the tree on the right is no longer rounded but sharpened off?

This will illustrate the trees contact with the ground.

Now we're ready to start adding our leaves.

Grab your number 6 brush again and select a dark green... preferably one that is close to a more khaki toned green, like the one I have selected in the images to the left.

With your transparency set to 60-65% begin to shade in the area around the branches you have created remembering to do so with one single brush stroke... not more than one okay?

Then we make a second brush stroke filling in a similar are to what we did with the first brushstroke. Continue to do this until you have a nice layering of the green as you see in the images on the left.

If you don't want your tree base to be as dark as mine is here then you would stick to only 2 or 3 brushstrokes for your tree leaf base.

When you're happy with this step, select a lighter yellow based green like the one I have in the bottom right image. If you move the color slider toward the yellow, but still staying within the green area on the flash tool, then you will be able to get the same green as the one I have here.

Grab your number 3 size brush and start filling in the smaller leaved area of your tree. Stick to the darker areas only.

When you're happy with the amount of leaves you have. Grab a lighter yellow leafy green like the one i have selected on the left.

Grab your number 2 size brush and here you will want to bring the transparency down a little to about 40%

Start adding in the lighter green leaves.

Being selective about where you add your leaves here will give the tree a more realistic look. Try making little patches here and there until it starts to look natural to you.

 

Now grab a more gray based green like the 4th color shown on the top left image. This color was taken from toward the lower left of the color palette in the same area as the lighter green color we used in the previous step.

Select a transparency again of around 60-65% and begin filling in around the lightest green colored leaves... When it looks natural to you, select a tan based brown like the bottom swatch on the lower left of the image shown. It should be toward a muddy tan gray.

Using a number 3 sized brush and a transparency of 20-30% add in some details to your trunk and branches. Stick to the left trunk and topside of the lower branches, higher branches can be either middle or top highlighted. You may want to switch between the 2 and 3 sized brushes for this step.

After that's done grab the fill tool at 100% transparency. We're going to use the background color (for the purposes of this illustration we'll choose white) to start taking little bites out of our tree here and there to give the impression of looking through the leaves and seeing the light behind. If you have a nice blue sky behind your tree, then you would use the colors of your sky at this stage.

Try to stick to the darkest areas within the tree for areas where you can see through the leaves and branches, making smaller and more cluttered nicks at the outer ares of your trees foliage will give a more natural finish.

I've added a shadow as the final step using a number 3 sized brush and a full black color with a transparency of 14%

I hope this tutorial helps you to feel more comfortable with drawing trees in your landscapes.

Thanks for reading. 

(source by : http://www.ratemydrawings.com/tutorials/landscape/2541-Intermediate_Tree_Drawing_Technique.html )