This is the first soft pastel  painting I did where I learned the most important techniques.  It is from this YouTube video that teaches how  to create this  painting.  I would strongly suggest you check it out.  

Blend or not to blend...this is a big question.   Many pastel artists will say, don't blend because it mutes the color.  This is true.  Blending does mute your colors and if you try blending the wrong colors together you may get mud.  Think about how colors work together.  For instance, if you lay down some blue and next to it some yellow, blending this together will give you green.  There are times when your blended colors will create a new neat color or effect but to avoid getting mud, lay your colors down and blend each separately.  As you work on your layers you can naturally blend colors together so it looks natural.  

Many artists will say only blend once in your painting. This is what they do because they use a painted first layer to set your colors.  Then they just keep adding and blocking colors.  It gives a Vincent van Gogh type of look and shows a lot of the underlying groves in the paper.  I am not a fan of this look but they do sell many paintings.  It is personal preference.  I say, if you want a smooth appearing painting, an underlying base of blended pastels is necessary.  Only the top couple layers are not blended unless there is a hard edge you want softened.  Then the blending is just a matter of a light touch with your finger or blending tool to soften a hard edge.  

One of the main reasons I like paintings done with soft pastels is the velvety smooth finish.  To achieve this look there are a few techniques you need to use.  Pastel paper has what is called, tooth.  These are small little groves in the paper which are there to hold the pastels you apply.  Filling up the tooth takes using the right techniques.  

Paintings are done by applying several layers of pastel.  The first layers are applied using light pressure of the pastels.  Skies should be blended in circular motions.  You can use different things for blending but I prefer my  best tools, my  fingers.  In the video here you will see him  begin by using the side of his hand to blend but I wouldn't do this unless my  paper is very large.  Keep a wet cloth handy and a dry one for whipping dirty fingers.  Yes, you will get your fingers very dirty, but it does wash off.  Always use clean fingers to blend. As you progress with the painting you  will see the colors getting deeper with each layer.  Then, use the  same colors without blending and the  effect will be brighter and more detailed.  To get the finest details, you  can  use the edge of the  harder pastels or pastel pencils.  

When doing water, blending the first couple layers is also important.  This  blending should be done in a back and forth way rather  than in circles like in the sky.  Water takes practice.  It can have ripples, waves, reflections, foam, etc.  Keep experimenting by using your pastels in different ways.  You can do your detail look by using short strokes, wiggles, blending and making the water smooth, using the edge of the pastel or lightly running the pastel over the water in horizontal strokes to simulate little ripples.  Have fun and play with your pastels.  Just remember to lay down layers using a soft touch and then pressing harder for the final couple layers to get brighter color and definition.

This is a painting I did recently.  I think it is a good example of how  blending makes your painting flow.  This is basically all water and sky.  I wanted the sky to have movement and the water to have movement.  To accomplish this feeling I used several blended layers. The layers were created using dark on the edges and then growing lighter towards the center.  The sun hits the  center of the water making it the lightest value.  As I blended the colors I let the lighter values gently blend into the darker areas creating a flow.  When you paint you will be creating a feeling in the painting much  more than exact details.  For instance, in this painting the sun is large but behind moving clouds.  Even though you cannot see a full circle of the sun, your mind tells you it exists.   

Paintings should be an interpretation of a photo or plein air (painting outside) or  even painting from a still life set up like a vase of fruit  or flowers on a table.  Drawing or sketching is all about each detail but painting is about creating the feeling or illusion of what you are representing.  For instance, drawing a leaf you would draw all the details of the leaf and use a little shading to give it form.  In painting you seldom do an actual single leaf but rather use different strokes and different colors blended together to give the illusion of a leaf.  To get a 3D effect in anything you paint use 3 lightly blended colors together to give it form.  A petal of a flower has a natural round look when 3 shades of the petal are used together and lightly blended to remove any hard edges.  A pink flower will have the pink for the overall flower, a very light,  almost  white pink for the  edge where light hits the petal and a dark pink or even a purplish pink to create the  dark areas of the petal where the light is obscured.  Painting is about creating something that your mind's eye will fill in as real.

Blending is  about creating a smooth  appearance and an illusion.  Next we will talk about blocking in colors.