The trouble you have with both of those inquiries is dealing with the arguments of the modalists and Sabellians.
Oh, I'm sorry. I thought you were asking for some ideas for teaching the Trinity. I didn't know you were trying to set the modalists and Sabellians straight. I've only ever met one, and he's a contrary lunatic. Can't tell him anything. Can't even offer him a suggestion or two. That's because he already knows everything.