What kind of digital post processing is used here?

[lisawang]

http://lookbook.nu/look/156475-Trapped-in-the-Closet-chapters-1-12
http://lookbook.nu/look/153074-Pleat-Dress
http://lookbook.nu/look/153726-Meandering-With-Scissors

I love these photos. (:

I've tried different cross processes countless times in striving to achieve a similar effect, with no success, at all. (clearly because I have no clue what I'm doing aha)

Any tips or advice would be much appreciated

[Isick]

It just looks like a partial sepia tone, I would have to see the original to know for sure.

What I would so is take your base image (layer 1) and duplicate it (layer 2)

With Layer 2 selected convert it to Sepia Tone (read this tutorial if you are unsure how to do that):
http://www.easyelements.com/photoshop-sepia-tone.html
** There are many other techniques to create Sepia tone, some featured on DEVPPL, but I find this way to be easiest.

Then set Layer 2's opacity to between 65 - 75%.

I am sure it isn't perfect, but without seeing the base image it is really challenging to see what affects were applied.

Good Luck!