General settings for overcast days??

We recently moved to Germany, and with the weather changing...it's almost always overcast, and dreary, and on the edge of rain.  I'm not pleased with the pictures that I've taken in the last few photo shoots I've done.  I am used to sun..which brings so much more life to the pictures.  I still think I can improve though on my current photo problem.  I'm shooting with a Canon Rebel Xti body, with a 17-55mm/f2.8 IS lens.  It seems most of my pictures are coming out with an overall haze.  I feel like even at 400 ISO it lets in extra noise that is unwanted.  I do a lot of family shoots with little children so a tripod normally isn't an option.  What do you suggest my settings to be at?