There's not much that'll help after you shoot.

"I won't run x camera over y iso" is basically the worst possible way to handle it.

I can shoot an image at 25,600 on the same exact camera and it'll be print worthy with little noticeable noise.

ETTR, man. That's what it excels at, improving the signal to noise ratio to help reduce noise. It works at low ISO, it works at high ISO.

ISO 12,800

_DSC3297 by Zack, on Flickr

ISO 20,000

_DSC3300 by Zack, on Flickr

This is *WITHOUT* any noise reduction beyond the lightroom import/export defaults.

Is there some background noise, sure there is. It'd still look good printed even without it, and this is a worst case scenario. Bright subject, dark background, shitty midtones...a noise nightmare.

Shot was done with ETTR.

If I was to perform noise reduction following the below steps, you'd hardly see any at all. NEVER do subject noise reduction, and NEVER do noise reduction in highs or upper midtones, keep it to the shadows.

Tips on noise reduction - duplicate your layer in PS - do the most heavy handed noise reduction filter you have on the upper layer. Turn it to mush, seriously.

Then, what you'll do is use blend if to only apply it to the shadow region, and use layer transparency to help feather it in a bit.

You can also use a color fill layer that's linked to the blend if to show you where it's being applied.

The ISO is the last thing you want to raise.

You want to over expose with shutter speed, aperture, or flash first. If nothing else will get you there, bump the ISO.

It will still help.

It'll give you less noise than just doing a normal exposure...and it'll give you even less noise than underexposing and pushing up a stop or three.