I've wondered how to develop N too.
N's please help us iNtuitards!
It depends on whether you want to develop Ni or Ne. I'm not sure which kind the following examples are, though.
Have you tried making lots of bad puns? If you keep at it, you'll eventually learn how to make good ones. Unfortunately, you'll probably irritate a lot of people before you get it right.
Another approach is, in a situation where you know what the expected response is... insert something that technically makes sense, but doesn't fit in the intended context. This is the one I usually use. I'm not sure if this is Ne or Ni, though.
Example 1: "What's up?" "The opposite of down."
Example 2: "What time is it?" "Time for you to get a watch."
Example 3: "Where are we now?" "In a car."
There's also the matter of coming up with new ways of doing things. Essentially, what this requires is a bit of thought. Try to focus on what is possible in the current situation, and avoid viewing it in terms of what's been done before. Just come up with a new way of doing something that you've done before, and do it in this new way, just for the heck of it (Though I would advise not doing this with anything important!). Even if it doesn't make any sense. Eventually, you'll get a better "feel" for what kind of ideas will work, even if you haven't tried them before.
Example 1: I'm out of knives, and I want to cut my peanut butter and jelly sandwich in half. Normally people wash off a knife and use it, but instead, I'm going to take a spoon, hold it by the scoop, and use the handle to cut the sandwich in half. Alternatively, I could carefully tear the sandwich into two parts with my hands.
Example 2: I want to read a book. I usually use the light of a lamp for this. I could also open a window and use sunlight if it were daytime. But instead, I'm going to turn on a flashlight and read the book using that. Alternatively, I could use the light of candles, a kerosene lamp, or night vision goggles.
Finally, there's learning to look at things from more than one perspective.
Example 1: From a power user's perspective, use of complex jargon and offering a myriad of options to configure is a good thing because it offers more functionality. From a normal user's perspective, this a bad thing because it results in more time and difficulty in figuring out how to do the task at hand. Neither perspective is wrong, they simply represent different priorities and goals.
Example 2: A smiley
)) could mean that someone is pleased. It could also mean that the person meant to enter a frown emoticon, but hit the wrong key. It could be used to mislead you, make you think they're pleased when they're really not. It could even be used sarcastically, indicating a happy mood in a situation where that is very unlikely.
Well, I hope that helps.