Developing your Ne/Ti synergy is a given.
But also, don't underestimate the power of developing your Si. Get disciplined and compartmentalize your life. I know ENTPs usually despise routine and strict schedule, etc. but to the well developed ENTPs with strong Si it really sets them apart. The organized scatter brain has such tremendous cognitive power.
As a poor example, I'll present an analogy. Say you drive to work at a new 9-5 job (in a stable secure career you plan on keeping because it is something you're passionate about, it pays well to support your family, etc.) the new building is a 25 minute drive away and there are many possible routes.
As an INTP I would approach it like this.
-Find one that works. Use it until I am familiar enough with it and I can make it a "go to" automated process.
-Now that I've become familiar with the route/area, find if there is a "better" route (to those of you who say, "oh well I would've just used a map to see the best route to begin with", I say "better" as in perhaps the most "direct" route is the one with the most traffic, and if you are trying to minimize travel time, perhaps there exists a slightly longer but less trafficky route). Make this a new routine/automated process.
I imagine some of you are probably thinking, "well duh" but the key is the emphasis on routine/automation, having the discipline to keep something consistent to the point where you don't have to think about it. This frees up your Ne for more useful, engaging tasks. There's nothing like being engaged, it naturally holds your attention. But as Cleese says in the video I'll post below, gently guide yourself back towards your end goal for the task at hand. I like to think of it as a person walking a dog. The dog should be free to roam on the leash as far as you let it, back and forth up, forwards and backwards, but ultimately it follows (for the sake of this analogy, anyway) the path the human walks. I know a lot of ENTPs see Si as being close minded, but believe me Si can be your friend, embrace it! You shouldn't have to draw upon your Ne to conjure up a new route every time you want to drive to work, let Si automation take over and then you'll only have to use your Ne once in a while, in the event the road is closed or something.
Use Ti to "hold on" to an idea until your Ne can nail it down in analysis, which you can then mark/flag with Si as "perfect"/"complete"/"understood". I think part of the "scatter brain" nickname comes from the fact that there is so much Ne going on that it is hard to mark things with Si, thoughts/ideas which are left as "imperfect"/"inconclusive"/"incomplete"/not understood" because they weren't held on to long enough by Ti, or not enough information was available, etc. Use your Ti/Si to tie up those loose ends and your Ne will be a lot more effective in future uses.
Another analogy... Putting my wallet in the same pocket. I don't have to stop to Intuit upon the last time I saw it or where it could
possibly be, I know, (for the most part) EVERY time I need to look for it, exactly where it will be. I had to use Ti to decide on where I will consistently put my keys/wallet/phone in my pants pocket. Don't go into Si routine right away though, after you have one that works, then use Ti to process and think about the best place to put it, e.g. you shouldn't get used to putting your phone and keys in the same pocket for it will scratch the phone, then you have to memorize/get used to a new routine each time you make an adjustment. Use Ti and Ne to foresee these things and decide on what will work in the long term. Then use Si to stay disciplined in sticking with it.
Si discipline is CRUCIAL in this process. If you don't stick to the rule you made for yourself, then you can't depend upon it in any of your automation, and you're back at square one except there's more thoughts/memories to cycle through before you remember "was this the new rule or the old one?", "Did I come up with something newer than that?", etc. Pick one and stick with it (it can be torture for an ENTP, I know). The benefits of having one or two very strong associations as opposed to cycling through a bunch of "open ended" ones are tremendous. It frees up your Ne to work on stuff you actually care about!!
I highly recommend listening to John Cleese's speech on creativity. It is so applicable to Ne/Si users (and others too). His views on the "open" and "closed" "modes" I liken to Ne and Si, respectively. (I believe he begins talking about it around the 8 minute mark or so.)
http://youtu.be/Hy_Iekv3214
Point being able to recognize when you benefit from the open and closed modes. Yes, most with Ne in their ego will prefer the open mode but don't underestimate the closed mode!
These, of course, are just my opinions. I should mention that I grew up with an ENTP so I like to think I know what I'm talking about
but feel free to disagree!
