Help with Deck-Building?

I've been gone for a while so I'm a bit rusty... I was just wondering if I could get any tips for deck-building and tweaking, and a few do's and don't (or an article that has the specified topic), I would appreciate it.

Also, here's a screenshot of my Infernity deck, I'd like to tweak it, as I plan on taking it into the Regionals:


BIG THANKS to anyone who responds. Thank you, everyone!

-Xixima

I believe that three Dark Bribes are a bit cloggy, and so removing at least one of them in replacement for something such as Solemn Warning would be good. Also, replacing one MST for Heavy Storm, and siding out the BTHs for Solemn Warning and another useful spell, maybe a second Pot of Duality would be good.

Not exactly brilliant with Infernities, so sorry if this advice sucks.