The best way to collect IMO is not to intentionally specialize, but to look at alot of coins and decide what speaks to you, and why. For instance, I collect primarily Roman Imperial bronze of the 1st & 2nd century, but I also have a small
collection of
denarii, and I also collect the early Imperial bronzes of
Antioch. Within each of these groups are small theme
collections, such as architectural reverses,
orichalcum asses, animal reverses, etc, etc. So my
collection has many different
themes that run through it, and this keeps me engaged, as there are many different coins that I can collect for different reasons. I feel that this approach makes my
collection far more interesting than would rigidly sticking to a single focus. My interest grows organically, many
themes upon which I collect would have never been revealed to me
had I not been open to taking some small
side trails off of the main path, so to speak. My advice would be look at many different coins, think about what attracts you and why, and read voraciously. Then just let your feet take you where they may.