Git - Criando um arquivo .gitignore

Eu estou olhando para criar um.gitignore arquivo para que certos arquivos não sejam verificados no repositório. Alguém tem um guia sobre como e onde colocar esse arquivo? Eu tentei colocá-lo no meu diretório de trabalho, executei o status git e ele ainda está pegando os arquivos que eu gostaria que ele ignorasse.

Eu usei isso.gitignore arquivo que encontrei:

###################
# compiled source #
###################
*.com
*.class
*.dll
*.exe
*.pdb
*.dll.config
*.cache
*.suo
# Include dlls if they’re in the NuGet packages directory
!/packages/*/lib/*.dll
# Include dlls if they're in the CommonReferences directory
!*CommonReferences/*.dll
####################
# VS Upgrade stuff #
####################
UpgradeLog.XML
_UpgradeReport_Files/
###############
# Directories #
###############
bin/
obj/
TestResults/
###################
# Web publish log #
###################
*.Publish.xml
#############
# Resharper #
#############
/_ReSharper.*
*.ReSharper.*
############
# Packages #
############
# it’s better to unpack these files and commit the raw source
# git has its own built in compression methods
*.7z
*.dmg
*.gz
*.iso
*.jar
*.rar
*.tar
*.zip
######################
# Logs and databases #
######################
*.log
*.sqlite
# OS generated files #
######################
.DS_Store?
ehthumbs.db
Icon?
Thumbs.db

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