Vasari is my primary race (after I decided to learn it, immediately following my original post about game balance, oh so long ago).

As such, my builds are the most matured, and most efficient of my posts.  I have never lost a 1v1 with Vasari (or any race), although I had one drawn out games that were left unfinished (draw).

You would think that I would have the most specific builds for Vasari.  You would be mistaken.  Vasari builds are more map dependent than any other, so instead of a flat build path as I've done in the past, I will go over the THEORY AND EXECUTION of the Vasari.

THEORY:
Vasari have excellent map control with Navigators.  Against non-Vasari, you will take every neutral extractor.  Against another Vasari, you will fight viciously over every neutral extractor.  This is how they are played.

The following Vasari units are terrific (in order of use):
1. Assailant
2. Subverter
3. Enforcer

The following Vasari units are counter units:
1. Sentinel
2. Skirmisher (to counter sentinels)

The following capital ships are useful in ORDER of usefulness:
1. Devastator Battleship (Mana burn + attack speed)
2. Marauder Battlecruiser (Free fighter squad at start + nice spells)
3. Dreadnaught (phase missle swarm + assault specialization)
4-5: other two.  Carrier sucks.  Why?  Repair hull is crap.  You will repair the hull of the ONE ship they're focusing.  Everything else doesn't benefit at all.  Compared to restore shields, it's an order of magnitude worse.

Basic MICRO tips:

Why are assailants so good?  Phase missiles pierce shield mitigation.  With focus fire, you can easily increase dps by more than 60-70% once you fully upgrade the pierce attribute.  With subverters, that dps increase is over 120%.

Micro assailants on weak units (light frigs) first for fast kills, then follow up on anything else you want.  Often in assailant wars, both sides will focus the capital ship.  This is a good strategy, but as it is with everything else, matchup dependent.  Do NOT focus fire kol (phase missle shield), Radiance, or Marauder (since it can phase itself out).  The NOTS are in order of importance.  Basically, NEVER focus fire a kol unless you're sure you can kill it.  It takes almost no damage from your missiles.

Do NOT focus fire flaks.  If they flak, you stop production of assailants, use existing assailants to kill light frigs + caps + buildings (IN THAT ORDER), and counter flak with skirms.  If they go carriers, you must go sentinels (obviously).

There is one more KEY to good Vasari play:
Holding off on upgrading your supply until you HAVE to.  Often, I will upgrade my phase missiles to tier 4 before I pop up simply because my opponent isn't being aggressive.  Assailants do not take long to build, especially if you build more than 1 frig fac (mid game, I have 3-4).

Finally, I will not be posting my famous RA rush here.  The skill is imbalanced, do not use it as a crutch.  Learn the game the right way.

EXECUTION:
The ALMOST ALWAYS techniques (EVERYTHING is map/strategy dependent):
Scuttle cap shipyard (why... not?)

Never start with skirmishers, they are overpriced and bad.  Start with assailants, and watch your opponent's builds.

NEVER go trade ports (unless you have a damn good reason, probably cuz opponents are scrubs).  Vasari trade port tech is tier 4, basically useless.

Start with devastator.  As you improve in the game, move on to the other caps.  The marauder is the hardest to use.

Here's a SAMPLE build order for 1v1/2v2 small map.  Remember, it's only a SUGGESTION.  It differs based on how much teching you can "get away" with before you upgrade pop as well as starting positions and neutral extractors.  Race matchup also plays a huge role.

This would be a medium map 1v1:

1.  Buy 2 units of crystal
2.  Upgrade home planet
3.  1 Worker on Cap ship, 1 worker on crystal
4.  Build 3-4 Navigators, scout and take neutrals
5.  Start Kortul when cap ship fac finishes
6.  Start 2 metal extractors
7.  Build colony ship
8.  Take nearby asteroid (all maps have 1 nearby asteroid)
9.  While taking asteroid, scuttle capital ship factory
10. Build military lab
11. Finish the asteroid, colonize it, upgrade so you don't bleed cash
12. Mine all asteroids
13. Start assailant production  (When assailants max your pop, and this doesn't take long, upgrade phase missiles twice, it's cheap and useful)
14. Asteroid #2 should be cleared and ready for taking (there's almost always a second asteroid, if not, find a lightly defended terran or desert)
15. Take asteroid 2, build it up as before
16. Now you have to make a choice.  You can add 2 more military labs (maybe even FOUR more), and continue research at 0 upkeep, or you can pop up and move out with your fleet.
17. You have 3 colonies, you can decide whether to take more or contest neutral extractors (good opponents will fight you over neutrals at this stage)
18. Pop up, and take a colony somewhere near the opponent
19. Build 3-4 Frigate factories, keeping unit composition to counter their fleet.  A level 6 kortul is also devastating with nanites.
20. Build subverters for shield mitigation decrease, enforcers to tank/dps if needed
21. Pressure with your mid game shield pierce army.  Eventually your opponent will fold.