What are good strategies for sealed deck?
Exactly the same as for draft, in terms of the BREAD rule.  Obviously that you don't have to worry about what to pick and pass: all that has been done for you, by the vagaries of random chance!  All that's left is to locate the most synergetic deck you can from whatever you've opened out of your boosters.

One thing I've seen the pros do, that I think is a great idea, is start off by checking your rares and mythics.  Oftentimes any truly busted bombs will be found here, and give you a good idea of what colours you want to find a way to include, if humanly possible.

Beyond that, the very intuitive thing holds true: separate your cards by colour and look for piles that contain lots of good creatures and efficient removal.  If you have two such piles, you're off to an excellent start!  Be careful though of possible mana curve issues: if you have two piles that are both stacked with great expensive cards, you may be better off going for a weaker colour that better complements your curve.

Don't get greedy and try to play a 4-colour deck, just because you have bombs in 4 colours: sometimes you just have to show some discipline.  Anything beyond two colours with a small splash of a third colour should set off some serious warning bells.  Having said that, don't panic that your deck doesn't seem as "bomby" as the decks you're used to drafting.  Sealed is typically a much slower format, with a bit more room to develop your position, and a bit more tolerance for the odd clunky card.  Though of course if you have the good fortune to be able to assemble a blazingly fast draft-quality deck out of your pool, you probably ought to go for it!