I'm trying my hand at Muscovy eggs right now.  Have never incubated any kind of duck.  My current plan is this:
 
1)  Starting Day 10, went to 5 minute daily cooling and misting.
2)  Incubate at 99 degrees, rotating twice daily with the x/o system.
3)  Weekly weighing, adjusting humidity as needed.
 
My first week they lost too much weight, so I did add humidity for week 2, a water reservoir with a sponge that dries out in 1-2 days currently.  Right now both vents are open, thinking this week I'll close one down.  It's really cold here currently, so very dry as well.  The incubator is a styrofoam type with air circulation.
 
Going into week 3 now, lost one that quit this week (had a detached air cell with free air bubbles when I got it) and had one clear.  12 cooking nicely with great veining and active little embryos.  I read that you ideally would like to see 2.8% weight loss per week.  The first week they dropped 4.1%, so I added humidity.  This week they dropped 7.5% (should be 5.5%) in the face of the humidity, so a little better, but still a little dry.  Don't know how worried I should be.  Am thinking a little dry is better than too wet...  Next step would be to close down one of the two little vent holes.
 
Will take any suggestions, have heard they are tough to hatch and have never hatched them before (or waterfowl of any kind).