Nice job, man.Here are a few ways that I can recognize different types. This assumes you are seeing the person acting as themselves and not projecting some persona. (warning: these are not sure fire, but they will usually point you in the right direction.)
ENTP - Very quick in their thinking and clever in putting their words together. Often do things differently for no apparant reason. Unconventional.
ENFP/ENFJ - Both are very charismatic and usually have tons of friends. Almost everyone loves these types. ENFJ's tend to be more focused and goal oriented. ENFP's are less focused and a bit more hands off in their approach to things compared to ENFJ. The tell tale sign of either is huge charisma.
ENTJ/ESTJ - They really want to be in charge, especially ENTJ. Both are very goal/achievement oriented. ENTJ's tend to be more open minded about things and aren't bothered by unusual behavior slide as long as the work gets done. ESTJ's are like ENTJ's but tend to want everything done a certain way.
INTP/ISTP - These can be hard to tell apart. Both are very aloof. Both can seem easy going, and yet both can seem overly critical. Both tend to not have much sympathy for overly feeling types. Usually the way I tell them apart as an ENTP is to start talking about hypothetical ideas. INTP's usually like to talk about these things, while ISTP's will not see much use to talking about these things.
INTJ - You have to get them to open up about what their thinking and then you'll get a glimpse into the unusual mind of the INTJ. They tend to make plans or schemes about everything. They also naturally look for the most efficient way to do everything even in cases where it would make no sense to most other types (like in their relationships to other people). They also speak with certainty but are more willing to change their minds than most other J types.
INFP - They often talk about the way things "ought to be". They are reserved, but optimistic. Actually their optimistic view on life can often seem unrealistic and they will often avoid/retreat away from you if you try to confront them on their unrealistic rosy view.
ISFP - They are often quiet and keep to themselves, but they tend to have concrete ways of expressing their creativity/individuality. Tatoos, a motorcycle, hanging their artwork everywhere...something. Be on the look out for outward expressions of who they are.
ISTJ - They seem the most grounded practical type. They can get irritated easily by what I would consider minutia. Very detail oriented people in general.
ISFJ - Like ISTJ but more polite.
ESFJ - Very warm caring individuals. They are traditional, but try to use the traditions to make people feel special, cared about and lifted up.
ESFP - Like to party and socialize. High energy, expressive and creative. Can seem ditzy and impractical too.
ESTP - Very action oriented. Also likes to party and socialize. Really a lot like the ESFP, but more logical.
INFJ - I'm married to an INFJ, but really I think tell tale signs are the hardest to discern with them. They can appear to be a variety of other types until you really get to know them well.
Your efforts are worth a resurrection of your analysis.
This is yet another evaluation that forces me to reconsider the accuracy of my apparent type...