Toss Waddle Dees from far away. Forward tilts, chain grabbing, and up/down air are all good damage dealers without knocking the opponent too far away. Down tilts are good for aggressive players; its range is deceptive and it has very good priority. Down smash for people who roll behind you.
Inhale also really throws players off track, and it seems to have the same properties as a grab: if you inhale somebody who's attacking you, you'll take some damage, but still inhale them. Super armor? Hard to say, as I'm sure many of you have gotten knocked out of inhale.
I've never really thought about racking up damage as DDD... it kind of just ends up happening.