How do I blend colors when painting a picture to make it look natural?

Im painting with acrylics, and the sky goes from light blue to dark blue. The last time I did something like that, you could tell where I used different shades and it didn't look that great. What can I do, any tips?How do I blend colors when painting a picture to make it look natural?
For the sky I start at the top and go dark to light at the horizon and then light to dark from the horizon to the foreground. I learned the simple rule of have some more fun. I sometimes wet the canvas and then apply the paint.





Check this man out for some ideas and tips.





http://www.simplypainting.com/





Here is a painting I did in acrylics%26gt;%26gt;





http://www.absolutearts.com/portfolio3/w鈥?/a>





Keep Arting! Jeff (weseye) Wesley