I find it funny that it matters that much to hide yourselves but the dog can be sitting there in the open. How does that make sense?
You can kill birds with the dog in the open. You can kill birds with you in the open too. But you will kill A LOT more with the dog hid and you hid.
Since we're on the subject of layout blinds... I like to position blinds (for right-handed shooters) so that they point slightly to the right of your killing hole. For a right-handed shooter it's much easier to swing across the left side of your body than the right. Positioning your blinds on a slight angle provides for a much more natural and comfortable shooting position, IMO.
Decoy numbers and layout... Pay attention to how the flocks are positioned in fields as you scout for the early season. You'll notice that the birds are scattered around the field in small groups. These are resident birds and they stick to family groups throughout most of the early season. Keep this in mind when setting your decoys. You may kill birds by setting one big glob of a spread, but I wouldn't take the chance... It's much more realistic to clump them up into family groups of 8-15 birds. You can strategically position these groups to create nice shooting hole just as easily as if you were setting a late season spread.
For ducks, IMO an absolute must-have is a jerk rig. This is the most underrated, underutilized piece of equipment amongst duck hunters. Spend 10 minutes of your life and make yourself a simple DIY jerk rig. Spinning wing decoys are great, but it's hard to beat the kind of water disturbance and turbulence created by a jerk rig.
One more thing I just thought of... THIS IS A GOOD ONE... When you're in the marsh and there's a break from the action or the birds quit working, go for a walk out through the decoys. Kick your feet through the bottom to really stir up the mud good. That contrast of dark muddy water you've just created will usually get the attention of every bird that flies overhead. Stirred-up water means active feeding... active feeding means "real" ducks... "real" ducks means safety... Ducks flying overhead convinced of food and safety equals what?... Dead real ducks.
Same goes for hunting late season snow-covered fields... Walk through your shooting hole and exposed the bare ground. Kick up corn stalks and dirt. That contrast against the snow convinces the birds overhead that there's food down there. These subtle little details that most hunters leave out can often times make or break a hunt.