App.Config

If you've not made use of the App.Config file then I strongly advise that you do! it enables you to store application level settings in a way that means you can edit them by editing a text file - no recompiling needed at all!

Probing Element

The Probing  element (Microsoft Link) helps us designate one or many subfolders for the application in question to look through whilst searching for bound assemblies (referenced dlls or exes) . I'd like to go into more about this element but essentially you can paste the below into your App.config and it will search through the folders lib and dll as subfolders of the assembly in question. This means that you can put all of your dll files in a separate subfolder!

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <probing privatePath="lib;dll" />
  </assemblyBinding>
</runtime>