Hiya,
Theres all kindsa different ways depending on what your going for, its something ive been playing with for the past year or two on and off.
First of all theres no right and wrong, its just what looks good to th eindividual eye, secondly.. lots of experimentation
You can tweak the colour, saturation and contrast levels in whatever software you use, you can deinterlace it and motion blur the frames in after effects to take away a bit of the sharpness that dv has.. or just dd a soft gaussion blur to take the edge off.
you can use plug ins like digi effects or magic bullet.. (which take ages to render and are expensive)
I also read in a thread somewhere tips from a guy who had to put dv onto the local tv station and came up with a process called INSTANT SEX cos it looked so much better. (i forget his name but credit goes to him)
It innvoles getting a clip and copying it so you have 2 layers of the same clip... on the bottom layer increase the contrast and saturation.. it will look awful but its meant to you. Then adjust the transparency of the other clip.. to between 50-80 percent.. that will bring the detail back and get rid of the washed out look that dv footage can have. Only trouble is the settings for contrast, saturation and transparency will be different for every clip so again theres no set way to do it.. just what looks good to your eye.
Basically you need a lot of time to play around with the different settings.
Any of this help you?