I have adapted a very simple rule for a long time now, if I use the
block for the side effect it is do..end, always.
If I use it for its return value it is { } always, (BTW thank you Rick ;).
But of course when I do side effects and use the return value I am
lost. (I guess that it is {} for one liners and do end otherwise than)

I know this was very helpful ;)

Cheers
Robert