can anyone suggest a good process for post processing to give a grad effect in photoshop?

well (as usual) it kinda depends on exactly what you want to do...

but heres something relatively simple to begin with, try this:

1) use the "Rectangular Marquee Tool" (selection tool) to select about the top 1/3 of the image
2) goto menu "select > feather" and try a value of 125

you have now isolated the top part of the image (with a "grad filter" type effect) for processing.

play around with this,
hope this helps,
cheers,

what I'll do most of the time is i'll use the

create a new field or adjustment layer button. (which can be found at the bottom of the layer palette)

Choose photo filter. Color is up to you. (this is good because it doesn't destroy your original image by working on the original layer. It creates a new layer above the original layer.)

Once done click on the mask thumbnail. (white box beside the circular shape) make sure it's highlighted.

Now click on your gradient tool and start your gradiantion.

Choosing photofilter gives your the right opacity to start out with. You can adjust the options on the filter. I hope this helps.

Add me in msn if you're unsure. Email is on my profile.

cheers!