there are thousands of tutorials on the internet, and here on this site....
just go to the tut section or google depth tutorial....
here is one about sharpning/blurring
http://www.photoshopessentials.com/p...epth-of-field/
lol not the easiest way of blurring...
I normally do apply image - then gaussian blur - then erase the parts that i want to keep sharp..........
or use the blur tool if you want little pieces blurred.......
or if you want to be more artistic use the smudge tool..........
as you see there are many ways to do it........
also what works for depth is lightning.......
if there 'shines' a l;ight on your focal and the surroundings are dark(er) then that adds depth as well....