Symbolic methods (operators) should always be invoked using infix notation with spaces separated the target, the operator and the parameter:
// right! "daniel" + " " + "Spiewak" // wrong! "daniel"+" "+"spiewak"
For the most part, this idiom follows Java and Haskell syntactic conventions.
Operators which take more than one parameter (they do exist!) should still be invoked using infix notation, delimited by spaces:
foo ** (bar, baz)
Such operators are fairly rare, however, and should be avoided during API design.
Finally, the use of the /: and :\ should be avoided in preference to the more explicit foldLeft and foldRight method of Iterator. The right-associativity of the /: can lead to extremely confusing code, at the benefit of saving a few characters.