I have been looking at graphics improvements for GW2 and I am currently testing Reshader.

Download it here... Reshader

You may want to place the installer somewhere other than downloads as it just runs straight from the icon and installs a dll to the game folder, this will allow Reshader to run within the game where you can configure graphics settings, I have a folder in My Documents.

You can download presets on install but there is a list to choose from here.

A note on presets
There are three main types of preset that use Reshader, they are Reshader presets, MasterEffect presets and SweetFX presets, I have only manged to get MasterEffect presets to work so far but having now figured that out I think I can apply it to SweetFX also, 90% of the presets are with these two.

Setup
Most of it is pretty obvious but a few things of note, GW2 is a Direct 3D game so make sure you select the correct API, unless you are using a Reshader preset do not select anything for this option, best to select performance mode other wise it slows Reshader down and unless you are intending to create a Reshader preset skip the tutorial, hit save and you are ready for the next stage.

MasterEffect Setup
Download MasterEffect here.

Unzip the MasterEffect folder and then copy all of the contents to the GW2 bin folder, next move the d3d9.dll from the main game folder that was created by Reshader into the bin folder and overwrite the existing copy and that is MasterEffect all ready to go.

To use a MasterEffect preset once downloaded open the file with notepad and copy the contents, now navigate to the GW2 game folder and open up bin, find the file named MasterEffects.h and open it with notepad and overwrite the contents with that of you downloaded preset and save.

Boot up GW2 and you should see the difference staright away, you can toggle MasterEffect on and off with the scroll lock key to compare.

SweetFX
Coming soon (Hopefully)

Uninstall
To uninstall Reshader navigate to the GW2 bin folder and remove d3d9.dll.

To uninstall MasterEffect navigate to the GW2 bin folder and remove the MasterEffect folder, MasterEffect.h and Reshade. fx files.