I've started to look at the relationship between these functions in order to differentiate an element being in the base or creative slot.
The base function is looking for any and all information related to it. It doesn't want anything to limit it, and will purposefully overlook other data in order to maximize it. The ignoring function is often related to information in the base function. The type will take it into consideration and has a strong knowledge base in the area of their ignoring function, and they may even offer advice in it. However, the moment that the information in the ignoring function somehow interferes with the information in the base function, it is dismissed all together.
The creative function is not as strong and not as much of a priority as the base function. Not only that, but the demonstrative function is ingrained into the individual's subconscious, and they are usually not even aware of how much the element affects their actions. The individual doesn't focus on their creative all the time, but when they do, there is always an implicit consideration of the demonstrative. The individual may not have any values related to their demonstrative, but they can't help but be guided by it.
With Fe base types, they are entirely focused on the implicit emotional dynamic that exists in peoples actions and interactions. They focus on manipulating or maintaining this in order to create mood that they would like to see. Most often this means upholding a positive, friendly, and fun atmosphere. While doing this they are aware of the bonds they are creating with others, and they enjoy creating these bonds with others. However, if they have to deal with being around people they dislike or if personal boundaries are crossed, they can easily overlook these personal fouls in the name of maintaining an atmosphere. They may even ignore the fact that they dislike someone if they see that person as fun to be around and contributing to interpersonal dynamics, and they will continue to put themselves in a position where they are around the person(i.e. invite them to parties, etc).
Fi base types have the opposite priority. They are very aware of how they feel about others, the implicit relationships that exist between people, and how to maintain, build, or break these relationships. They are skilled at working interpersonal dynamics and have to for the sake of their relationships. However, they refuse to dismiss their personal sentiments in order to maintain a friendly facade, and if pushed hard enough will even break a whole group dynamic because of the way they feel about a particular person and how they're acting. Fi-base types know that interpersonal dynamics don't always reflect what kind of relationship exists, so they will usually ignore them when determining what kind of relationship exists or what they would like to exist.
Fe creatives are like Fe-base in that they focus on interpersonal dynamics. They are aware of how they can change an atmosphere and manipulate emotions. More often than not though, they simply observe the changes going on, and are only occasionally driven to push things into a different direction. They form strong opinions of people and become clearly aware of the implicit relationships that are built and how they are built. When they do act on the interpersonal dynamics going on between people they do so with the consideration of how they feel about individuals involved. For example, they're not likely to act like best friends of people they don't know or dislike. Like Fi-base, they cannot ignore the relationships they have with people or the lack there of. However, they don't emphasize their personal feelings or implicit relationships the way Fi-base does, therefore they are unlikely to overtly ignore people they dislike or cling to people they like.
Fi-creatives focus on implicit relationships just as Fi-base does, but with a lesser priority. They aren't as focused on stable relationships as much as they like to change relationship or establish new ones. When their personal sentiments change, the way they interact with people changes to reflect it. Like Fe-base they are constantly changing the emotional atmosphere, but they tend to let themselves be emotionally free, always expressing their personal feelings. They don't feel the need to control an emotional atmosphere the way Fe-base does. Instead they subconsciously change it on a whim by letting their actions reflect their changing personal sentiments.
Te-base are focused on particular cause and effect processes in the external environment. They know well how to manipulate things and make them work the way they want them to. They have a strong orientation toward tasks as they are drawn to produce beneficial results from their actions. As they are involved with these external processes they find general patterns and rules that can be concluded from the world. They can build a pretty strong knowledge base in this way. A potentially infinite number of conclusions can be drawn from the facts derived from the external world. Te-base are skilled in these comparisons and logical conclusion building, but they have a need to consult reality. If a structure becomes too far removed from reality, they become uninterested because it doesn't help them interact with the world and distrustful of it's accuracy even if it is logically valid. They may be reluctant to jump to conclusions even when it makes logical sense. If there's no external basis, it should be questioned.
Ti-base is focused very heavily on what does and does not make sense. They are always aware of whether things fit together logically or not, and they are skilled at following a logical train of thought and coming to a logically accurate conclusion. They are well aware of the practical workings of the world and often refer to it in order to get more information from which more conclusions can be built. They feel little need to interact with the world though. They can much more easily learn about reality through reflection and conclusion building. They can be prone to dismissing evidence that contradicts their logical conclusions, because there are always exceptions to the rules. Often they will try to reclassify the contradictory fact in order to explain why it was an outlier. Unless enough external evidence is shown to prove something to be incorrect, they won't let go of guidelines that represent how reality is at least most of the time, and even then they prefer to understand the logical reason they were wrong before accepting the evidence.
Te-Creative are focused on causal functioning of the world. But, they spend less time directly involved with the world unlike Te-base. They spend more time observing the processes taking place and they begin to build an understanding of how it works. They also become aware of the various explanations behind why the world is the way it is. When they do interact with their environment they are guided by how they understand what they are interacting with. However, they know the limitations of logical analysis and will quickly let go of explanations which they cannot rely on when interacting with the world. For them, evidence always trumps explanations.
Ti-Creative are focused on how they understand the world. They build and deconstruct understandings very often and quickly. They like the exercise of discovering new ways of explaining the world, but they are not concerned with maintaining all-encompassing systems the way Ti-base is. While they enjoy coming up with new insights into why the world is the way it is, they are also always aware of the empirical evidence of how the world actually works, and take note when their explanations are not supported by facts. Contrary evidence causes them to question their logical analysis sooner than Ti-base, and they will freely adopt new explanations if they can find them. They find themselves deriving new patterns and ideas from processes occurring in the world, and this is because they are continually subconsciously taking note of all the ways in which the world functions. However, they are aware that there is more to the world than just the observable workings of it, and consequently they feel free to follow logical trains of thought beyond what fact and evidence can prove.
(Thanks to Krig the Viking)