I thought I'd get this subforum moving with some thoughts. I might get to the rational elements eventually. I find irrational elements a bit more basic and raw.
This is my attempt to get into the mind of a type. I'll just be focusing on the base and hopefully get perspective into comparative types. Let me know what you think, and I'd especially like to hear from irrationals and how they relate.
Looking at things from the perspective of Se is simple but also strange to think of for non-Se types. To see things as an Se-base sees things you must look at what is in front of you. No really, just look around, look to the sides, and look up and down and get a look at what's are you. Now think of being locked in this state of awareness, but make sure you're looking around and focused only on what you see. Don't let your mind drift beyond the immediate reality, keep on it for at least a minute or two. If you do it long enough you may start to become anxious. Like your mind is starving for something. You may feel the need to move something or change something. You may get the urge to just jump up and move around or maybe leave because your surroundings aren't doing anything. They're familiar and boring. If you are in a place with a lot of action and movement, you'll find things that catch your eye. The things that you catch with your eyes are big or loud in some shape or form. You may catch a flashing sign or a colorful dress, or a guy who is just to muscly for their own good. More often than not, you notice 'strong' or 'impactful' things, things that stand out among everything else, and something is attractive about it. You can't get your eyes off it. Being in the middle of the action gives them a rush and makes them feel alive and pumped to handle anything as it comes(edit 10/17). This connection to their surrounds makes them well oriented on reality. They become so adjusted to things being as clear as day that they often take that approach to everything and can seem rash as a result, but often they have have the self-confidence and drive to take on any challenge that may come(edit 10/17). Being so connected to their immediate reality, they're often driven to make their own impact on the world.
Getting into an Si state of mind is similar to an Se state in that it is sensual, but there are some important differences. With Se you are focused on the environment, but with Si you are focused on the feelings that come from looking at the environment. The Si mindset sees it's surroundings well, but it does not 'stare', it 'feels.' When you look at a flower, its beauty is striking. The colors are so vibrant that it causes some reaction in your mind. Red can be intense and inspires passion and you feel as the rush comes and goes as your eyes sweep over it. Blue brings calm and tranquil states of mind and you feel as the color relaxes your body. The same goes for any external perception. You feel how a cool breeze causes a shrill-like feeling across your skin. As you are aware of how these thing affect yourself, you can usually judge very well how the same scenarios are felt by others. "I have felt x when y happened and now my friend is going through y and must also feel x or something similar." For every external happening or even remembrance of something there is a physiological and psychological response, and Si is very aware of all of these connections. All types of pleasure and pain are felt acutely by them and they know well how to control and produce them, but most of the time they prefer to take it as it comes.
Ne is focused on the environment the same way Se is, but with a key difference. Ne types don't focus on the reality in front of them. Instead they the environment inspires thoughts which they attribute to the things that inspired them. In attempts to get into the mind of an Ne type, look at something around you and now pay attention to what happens in your mind. What does it make you think of? Is it similar to something else you've seen? What kind of characteristics do you think it has? Is it capable of something? Likely you will exhaust your surroundings in mere moments if you're in a familiar place. You've seen it all before, there's nothing left to inspire you. Like being in the Se mindset, being focused on the Ne mindset without a change of something to focus on will cause your mind to starve for information. You can't sit and do nothing. You want to find something else which can spark your interest or bring up new questions. Ne types tend to uncover many new and interesting perspectives on things. They may even seek to find other's ideas and thoughts to inspire more of their own. They have a natural inclination to see 'into' things and pull out new thoughts and possibilities for them. Their usually fresh perspective on reality often makes them a source for innovation and reinvention.
Ni types have a perception that is furthest from reality. Getting into their mind takes an almost meditative-like state. You must shut out reality and focus on the images that come from your mind. Try sitting in complete silence where nothing is going on, and close your eyes and just be open to what comes to your mind. The images and memories that come about in this state are what Ni focuses on. This is the perception that carries the most weight for an Ni type. Their external awareness fades in and out as they are naturally focused in on these mental images which are independent of any immediate physical input. This focus that is drawn away from the immediate moment forces them to think about events of the past replaying them in their mind. They begin to see things that they didn't see the first time around and become aware of the interrelatedness of events that have occurred. They become naturally inclined to imagine how events in time lead from one to another and become aware possible future outcomes. They are aware of how they can influence the future and often aim to do so, but at the same time all the factors that are involved can be overwhelming and they are often not capable of causing great change as they are only one person. Often they prefer to just indulge in their mental imagery as there is far more complexity and meaning in their mind than there is in reality.