I ran two batches this year. first batch I uses .5 tsp of spices like most recipes call for and couldn't taste the spice. I have a feeling the problem came from adding the spice with 5 mins left in boil they say spices are volitile and loose flavor after boiling.
Second batch I did with twice the spices and dropped them in at 2 mins left in boil. It's not ready yet, but I tried a sip when transfering to secondary and was much happier with the spice.
I think 2 mins is the key here, but I would recommend the following:
1 - 1.5 tsp Cinnamon
.5 - 1 tsp Cloves
.5 - 1 tsp Allspice
.5 tsp Ginger
.5 tsp vanilla extract
I must say though, The batch with no spice flavor was still terrific. Kegged it for a Halloween party and it was a hit! That said, maybe start on the low end for your first batch.
Oh... did I mention only add it for 2 mins?!