What Russell has provided is pretty good.
However I found the biggest secret to comfortable sailing on the Serenity is fin selection.
What fin are you using?
The stock fin that comes with the board is probably the hardest fin you could find to jibe on the Serenity.
I've found that a 60-64 cm vertical race fin is far better overall and makes the board much easier to jibe.
Hope this helps,
Once I know what fin you are on, then I may provide a bit more info on the technique I used to jibe the Serenity.
My technique is a bit different than Russelll's.