My Java code has improve dramatically since I started (ab)using Optionals.<p><pre><code>  String foo = Optional.ofNullable(paramater)
                       .filter(...)
                       .map(a -&gt; ...)
                       .map(b -&gt; ...)
                       .orElseGet(() -&gt; ...)
                       .orElse(defaultValue)
</code></pre>
Between this kind of thing, and similar playing with Streams, some of the ugliest code I work with is suddenly quite clear, coherent, understandable.