How can I delay a method call for 1 second?

Best way to do is :

[self performSelector:@selector(YourFunctionName) 
           withObject:(can be Self or Object from other Classes) 
           afterDelay:(Time Of Delay)];

you can also pass nil as withObject parameter.

example :

[self performSelector:@selector(subscribe) withObject:self afterDelay:3.0 ];

performSelector:withObject:afterDelay:

Document Reference

You could also use a block

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
    [object method]; 
});

Most of time you will want to use dispatch_get_main_queue, although if there is no UI in the method you could use a global queue.

Edit:

Swift 3 version:

DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
    object.method()
}

Equally, DispatchQueue.global().asyncAfter(... might also be a good option.