Well dont know about PSP7, I use Elements 3. I can give some basic tips. I try to select all thats the background that I dont want to sharpen(if its a shot with that in it,or all the image if none of that). Since I know the cam you are using,if you have a background you want blured then go ahead and gaussian blur the background some, I usually use 1 or 2, depending on how much an effect I want. Then inverse the selection and then you can use the unsharpen mask. I usually go with a radius of 1.1, threshold of 0, and play with the strength(depending on what it is) from say 125 up to no more than 200. This is a good starting number to try, just practce and you will get the hang for it.