Hi Leon,
I kind of really decided to go the way of the type card route after I found this message board and saw your collection.
My initial inspiration was looking at my old copy of Sports Americana and saw Barry Halper's collection and decided to get some of those type of cards and those in that catalogue. My goal was to get one HOF card or a really good looking player photo or design from major card issues.....and early on decided to get them in "collector" grade so as to be able to not only collect more, but also leave enough $'s in my pocket. Luckily this was in the early 80's so cards were still relatively cheap... that's how I ended up with 52 T Mantle, 33Goudey Ruth and a T207 Lowdermilk. From there, I started to focus on the major E card series and then to Exhibits and so forth....
I have few rules and criteria....but its not always set in stone..lol. For example in some issues I don't really care too much about back variations so I only have 3 T206 cards (one regular player card, one minor league and one horizontal pose)...but for Exhibit cards, I look for examples that have coupon offers, ads or post card backs...
For cards that come with tabs or coupons I like to get those that are intact..
It's really been a fun journey so far..and with type cards I never get bored!
Ricky Y