How to Change the Sky
 

I've been trying to make the sky in this picture more blue in order to make more of a contrast to the ice on the bay. I'm using PS& and I've tried everything that I can think of. The picture isn't too good but I would really like to figure out how to do this. Help, please!

A simple way of doing it is to make a rough selection of the sky with the lasso tool, don't worry about going over the tree tops but keep it tight on the horizon.
Go to image-adjustments-selective colour and choose whites from the drop-down menu. Tick absolute. Move the black slider up a bit till you get a grey sky, then move the cyan slider up and yellow down ... and generally play around til you get the blue you require.
If your not happy with the resulting blue... go to hue/saturation section and select cyan from the dropdown and then have a play with the hue/saturation/brightness sliders.

cheers,
Andy

Thanks, Andy that's exactly the sort of thing I needed to know.