suggestions on duck houses, geese houses, etc

[RoyalHillsLLC]

I freerange my birds on about a 6 acre partially wooded pasture with no pond (use large washtubs with float valves).
I sometimes have difficulty getting my chickens to lay in the pen and have to pen them for a few days to get them back in the habit. Next spring I will have way more birds laying than ever before (about 30 I hope). Many of them will be Muscovies and I have 5 geese, in addition to my chickens.
I have been looking for nesting box ideas. Any thoughts on cheap options that they will use? Can you scatter them around your pasture or do they need to be in or near the pen you use at night? Will the ducks and geese come back to a pen once they start laying good? I have debated just stopping penning them next spring as my guard dog will be old enough to keep away most coons (I hope).

 

[DuckLady]

Waterfowl generally lay in the morning. Mine are done by 8 or so. I lock mine in their pen at night. They will use straw, but they have never used a nest box. I just pile some straw in the corner of Duckingham Palace and they either use that or just drop the egg in the nearest blob of mud.

I only let mine out of their pen after 9 am or so.