I've just recently started playing DoNs and though I've only played 18 so far, I've won 16 of them up to the $20 level, so maybe my strategy is sound. Guess I'll know better after I've booked 100 or so of these.
Obviously your strategy at any given moment changes based on stack size, blinds, opponents, etc. like any other game, but it's important to remember that in DoNs you're not playing for 1st, but for 5th. This deviates from your typical SnG strategy. The standard approach I've been taking is to flip the usual SnG strategy upside down, i.e. play LAGy early on to steal blinds, trying to keep yourself in the top 3 stacks at all times, then tighten up as you approach the bubble. I find that people tend to play more conservatively early on, presumably thinking if they conserve their stack from the start it's easier to make top 5. But in reality doing so often relegates them to being stuck in the middle of the field, where it's way too easy to find themselves out in 6th or 7th place. Especially when there are a few LAGs scooping and stealing to build their stacks early. Waiting for premium hands will be a disadvantage against LAGs who play a good positional game with ATC and slowly but steadily build up their lead -- when you finally get that premium hand and play it, they'll recognize it and not pay you off, so you don't gain enough to either help yourself or hurt them. Unless you get lucky with a suckout, or running nuts against 2nd nuts, it's often hard to get paid off in that situation. Remember that in poker, and especially tournament poker, your cards are only 1/3 of your arsenal, you also have chips and position as weapons, and can often use either or both as a substitute for good cards.
So you want to build up your stack early, THEN when you get close to the bubble with your top 3 or so stack, you can slow down and avoid marginal situations while the short stacks have no choice but to desperately scramble to make top 5. Remember, you're playing for 5th place, so your focus is less on overtaking the chip leader as you would in a regular game, but rather on eliminating the shorter stacks or keeping them short so they eliminate themselves or each other.
For instance when we're down to the 6-handed bubble and I'm a top 3 stack, I'll often fold hands like JJ and AQo to preflop raises from the other medium-large stacks (of course I'm calling a shove from a real shorty though). Also, I avoid calling SS shoves with total crap or coinflip hands even if I'm the top stack. As opposed to a regular SnG where you might be priced in to call with almost ATC, in a DoN you want to keep them short and in danger -- while losing wouldn't hurt you greatly, doubling them up keeps them in the game longer and poses a greater risk that they'll come back into top 5 position, potentially displacing you! I'd rather let the shorties tangle with each other, or let one of the other frisky big stacks bully the shorter stacks around. Since final chip count doesn't matter as long as you're in the top 5, my goal isn't so much to accumulate ALL the chips, just enough for a comfortable buffer. So if I'm in the top 3 or better I slow down, take very few chances, and protect my stack.
On the flip side, the few times I've found myself on the short stack, I push really aggressively, especially towards the bubble when others are trying to survive. Then once back to a comfortable chip position, I change gears again.
Obviously if I happened to pick a table where everyone else thinks the same way as me, then I'd adjust the other way to try and exploit them, but so far in my small sample size I haven't really seen it -- most everyone plays pretty nitty early on, then scrambles to play catch-up later. Until I book a significant losing streak, I'll keep on with this approach.