Question on Duck Hunting Scenario - Flooded Timber

This past season I spent time hunting some public land in LA. The area I was hunting was basically a bunch of flooded sloughs broken up by ridges. The sloughs were mainly cypress and tupelo gum but there were also areas of flooded oaks that were dropping acorns. Some of the sloughs were over a quarter mile wide though, so we're talking about a lot of flooded area. I would guess that half of the total wooded area was flooded.

There are a couple of lakes back in the woods that I knew about in the middle of the flooded timber. I spent most of my time trying to hunt one of them, and I was successful at killing a buttload of wood ducks, and a few mallards (1 per hunt basically. If I'd shot better I might have gotten another 1-2, but I didn't have more than 2-3 opportunities a hunt at most. Sometimes just one.). I knew there were more mallards in the area, because I'd jump up a few on my way in/out (maybe a half dozen here and there). I never put any time in trying to find out where the birds were coming down in the sloughs because I thought having some decoys in a lake would be a better bet.

Long story short I had some decent hunts but never had more than a few opportunities at big ducks. I think my mistake was never moving off the lake and into the timber. It's not possible to get a boat into the area (except maybe a pirogue if I drag it in a ways first).

Couple of questions:

1. How would you approach trying to scout for big ducks in an area like this? My inclination is to hunt the first hour or so and then spend the rest of a morning/day looking for big ducks, then come back to the same spot the following weekend.

2. Will I scare the ducks off of a spot by flushing them out if I'm walking/paddling around?

Also, I do acknowledge that without better scouting into the timber, it's tough to say that I'm in the right spot at all. Thanks for the input if you made it this far.