Since I always declare private properties in the class implementation file it's nice to have new class implementation files already include a class extension.
This is my template file for doing this. You change the template in Preferences->File and Code Templates->Templates->Objective-C Class.
#parse("Objective-C File Header.m")
#import "${HEADER_FILENAME}"
@interface ${NAME} ()
@end
@implementation ${NAME} #if ($PUT_IVARS_TO_IMPLEMENTATION == "true"){
}
#end
@end
@JanC it's in 'Code Style | Code Generation | Put ivars to implementation'