Hi,
I used to live 80 miles from the Philly Mint and almost never saw a D mint coin.
Being in the Pacific NW, I now see almost all D and S coinage with a smattering of Philly stuff.
I have found Doubled die varieties on the obverses of 1972 D, 1984 D, 1985 D, 1989D, cents. I have not found a 1995 D
DDO yet but I'm trying:-) I am certain that there are others but these are ones I have first hand knowledge of.
Repunched mintmarks can be found especially on the Memorial Reverse cents, 1959 D to 1963 D have many to offer.
There are some others in the 70s and 80s so check them all:-).
On the 1970 S small date cent, it is easier to look at the shape of the 9 and the way the upright of the 7 meets the top. Compare the pictures here.
The 9 is the easiest thing to use as the small date cents have a 9 where the inside loop ends in a point. The large date cent has the end of the inside loop more rounded.
Here are Chucks pictures, this should make it easy. Looking at the zeros and the height of the 7 vs. the 0 will drive a sane person crazy:-)
http://www.thecentproject.com/sort1970.php I hope this helps. In short though, check everything carefully. D mint stuff seems not to have been scrutinized as heavily as the Philly Mint coinage over the years so new discoveries can turn up.
Have Fun,
Bill