Hey, there are a few detailed ones available online but I generally just mark the temp and source files for a project to be ignored like this.
# Ignore all Intermediate and Saved directories
*/Intermediate/*
*/Saved/*
*/DerivedDataCache/*
*/Build/*
#Ignore resource files
*/obj/*
*/fbx/*
*/psd/*
*/tga/*
For the engine build you can add a few more
# Ignore root Visual Studio solution files. We do check in some sln files in subdirectories, so only ignore
# the ones found in the root.
/*.sln
/.p4sync.txt
# Ignore all Visual Studio temp files.
*.suo
*.opensdf
*.sdf
/Engine/DerivedDataCache/*
**/DerivedDataCache/Boot.ddc
**/DerivedDataCache/**/*.udd
# Ignore all Intermediate and Saved directories
*/Intermediate/*
*/Saved/*
# Ignore UBT's configuration.xml
Engine/Programs/UnrealBuildTool/*
*.uatbuildrecord
# Ignore built binaries and temporary build files
*/obj/*
*.csprojAssemblyReference.cache
# Ignore UBT's log output files
/Engine/Programs/UnrealBuildTool/*.txt
# Ignore Python cached files
*.pyc