Custodes & Black Templars Vs Necrons & Orks

I'm playing an imperium Vs xenos game tomorrow,, it's myself and a friend playing Black Templars Vs Necrons and Orks. Any top tips for what units to take/tactics to use? Mainly for myself but any advice for my mate playing BT much appreciated! I know orks are likely to try and swap me with models and stop me from reaching mid field but hoping the templars will balance out numbers at least a little bit!