Good chance you'll lose a lot of aroma and flavor of these during primary. So, be prepared at bottling or kegging to add a little more to taste.
I used a spice mix of equal parts cinnamon, ginger, nutmeg, clove, and allspice. This is what I added at bottling to taste. I believe I did 1 tbsp in vodka.
For the mixture at boil, I followed the pumpkin pie spice recipes I found online at foodtv with those same spices but in different quantities.
I was talking to my local brewer about their pumpkin ale that's coming out next week a couple days ago. They used crystallized ginger and whole spices. I'll probably try that next time, except for nutmeg. Those are expensive and a little goes a long way.