Consider using the one used by default by your IDE's reformatter mechanism. Will save you a lot of time in the long run.
We enable save actions in Eclipse and tick Format Source so the sources always are reformatted. This means that a reformat only changes things happened since last time the file was saved. Is nice in source control history.
You can naturally take your time and define your own format, but it tends to be easier just using the Eclipse standard - it is ok for us.