What techniques would you use to even this out? Two other people in this photo have whites clothes on and it all looks like this. Thanks!

Well, I guess there's two ways to do it - the quick way or the neat way.

To do it quickly, a filter like Surface Blur, or Median (in Photoshop) would help you out.

Or you can get up close and personal, and blur or clone every little bit. It depends on how much time you want to spend vs what quality is expected.

By the way, sometimes you can get good results with something like this by scanning it in colour (even if it's a black-and-white original), because sometimes there's subtle differences in the colour channels, and you can pick the best one. My apologies if you already know about this.

In order to maintain the detail...
- duplicate the layer, change the blend mode of the copy to "exclusion", then lower the opacity to about 30% or so.
- either create a mask and paint over all non-clothing items with black, or select all the clothing before creating the layer above so you'll have a mask that allows the blend mode to only affect the clothing.
- then use the healing brush to touch up the few remaining spots.
- also experiment with the healing brush set to "lighten" blend mode on darker spots, or "darken" on whiter spots.

Hope this helps !

Thanks to both of you for your help. I did a bit of cloning, then I followed your instructions Tommy and things worked out rather nicely. The healing brush really made it all come together. Thanks again, I've learned something, I really appreciate it!