... to use against Miraak? Since I am about to meet with him in a final battle, I mean apart from using the dragon skin on yourself, I wonder if mark for death would be better than fire breath, etc. What do you suggest?

Kyne's Peace.

Seriously, Marked for Death is always good to open with. I find it a bit cheap though. If you want the fight to be VERY easy, use Storm Call. It actually works!

When I fought him, I tried to use as many shouts as I could (it felt fitting). This included Dragon Aspect, Fire/Frost breath, whirlwind sprint, Unrelenting Force, Elemental Fury, Slow Time, Become Ethereal, and Cyclone.