It is way easier that in previous versions of TFS, simply create a .tfignore file.
For example:
######################################
# Ignore .cpp files in the ProjA sub-folder and all its subfolders
ProjA\*.cpp
#
# Ignore .txt files in this folder
\*.txt
#
# Ignore .xml files in this folder and all its sub-folders
*.xml
#
# Ignore all files in the Temp sub-folder
\Temp
#
# Do not ignore .dll files in this folder nor in any of its sub-folders
!*.dll