.net application causing memory fragmentation

I understand that only way a .NET application ( that does not use any unamanged code) can cause memory fragmentation is by large object heap. Are there any ways of detecting if your a开发者_StackOverflowpplication is fragmenting memory and anyways of avoiding it?

1. Keep objects small.
2. Keep objects short-lived.
3. Trust the GC

1 and 2 might be tough in practice but honestly, you'd be talking about BIG objects and the GC really does a good job with all this.