The very important first step is to know what you want to draw. Eventually make a sketch with just a few lines to know at least the composition of your paiting. This doesn't have to look nice. You can do it rough. Make a sketch on paper or in any background program, or use a scanned image or a Google image on the background (alt tab) or on your second monitor. It's usefull to have a reference next to your plain white paper. Believe me.

Use Google to find images about subjects and use them as inspiration. If you want to create a monster for example, just Google exotic animals and find a picture you like. Now you can be creative. Make a caricature from the picture by enlarge specific parts, adding horns, tentacles over the original image. You just created a monster and have the composition already fixed.
Find a WW2 tank image, Google Fantasy vehicles and combine both pictures for example.
Make a raw sketch for the composition and enjoy.
You can do this with any subject for a daily challenge or with the inspiration button ingame [shift] + W

For anatomy use a classic manikin (wooden anatomy doll) or Google "3d posing doll online" to get a list of websites with pre rendered poses (for example http://www.posemaniacs.com/ is a good site to find any pose you want and move them online in 3D with grid).

Use the program to your advance. Use the QWE ASD ZXC to select your tools so you don't have to switch the position of your hand constantly. If you use a pencil you can doubleclick any tool or color with your pencil and don't have to use hotkeys at all.
Next, zoom in as much as possible in the picture you want to create. You can almost work pixel per pixel if you zoom in max and you will be surprised how good your pictures look when you zoom out again. Use the zoom!!

Start drawing your first raw sketch on the paper. But before doing that choose what background color you want to use globally. You don't have to start always on a white background. Choose a color and choose the largest brush and recolor the background of your painting quickly. After that, start making a rough sketch with the Q tool set to minimum and imagine you are sketching with a pencil on a paper.

When sketching it helps to organize the screen in front of you in a grid/raster. A 3 x 3 raster works fine most of the time. You can eventually draw that raster on your screen since you can remove it later. It's a good way to know where all the parts exactly have to fit on the screen. You use the raster to make your composition. It prevents you when you start making a head to find out you don't have place for the legs anymore.

In detailed work you can use that (imaginary) raster how many times you want. For a face for example you make an eclipse and divide it in a 3 x 2 raster. You know globally where the eys, the mouth etc have to come at forehand. Making the eye? Zoom as much far as possible in to the eye and paint pixel by pixel with the W brush.

When your sketch is complete you can take a look at your detailed or rough example again and look at the image like you are looking to common shapes. Reduce the amount of shapes as much as possible but try to organize everything in circles, eclipses, triangles, squares etc etc Now draw those shapes in your sketch.

You can now color the shapes. Don't forget to take a look at your background again first. It's better the main colors for the background are done already, since it's much harder to fill in this afterwards when your foreground images are already created.
You don't have to be precize when coloring the shapes. You know have an image on your screen with colored parts exactly on the place you want them to be. Congrats. The basics are done now.

Now you have your sketch with colored shapes you can start to add details. Always start to paint with the color most used in the specific shape. You can use a black (or any other color) with the W brush to specify borders, you can delete them later.

Try using some shadow effects by imagine a lightbulb on the upper right part of the screen. Now take a color slightly more dark and use that color in the left part of the shape. Eventually take a slightly lighter color for the right part of the specific shape.

If your lightbulb is on the upper left you do vice versa for the coloring. You can even place it up or down!

On the dark parts you can add highlights with a white W brush and holes and folds with the black W brush. You now created shadows.

For detailed work I will do another guide in the future. As a sneak peak I will share one trick that works very well in Painter's Playground to fill in detailed shapes without reaching the edges.

Tip #1

Take the W brush, and make a slight circular movement with your hand constantly. That way you can be most accurate on the edges, you just keep circling till you reach the edge.

That's it for now! Hope you can use some of it for your own paintings.

Cablenexus