Listen, I won't make a long guide, but just some helpful tips.
As Vasari:
First cap-Jarrassul Evacuator, i don't see any reason to differ from this
As TEC
First cap-Marza Dreadnought, really just great at expanding and the Missle Barrage ability just cleans house
As Advent
First cap-Progentior Mothership, it is a useful support cruiser with moderate firepower. The Halcyon Carrier is also helpful because the Telekenetic push ability is like flak, throwing around fighters.
Some people dont understand when to go for economy, which is essentially building trade ports or orbital refineries. The real answer is that you shouldn't do something like this if you aren't going to be in the "pocket" protected at the flanks by allies in team games. Your job then is not to play sim city, but rather to give your allies a boost in the form of credits, metal and crystal.
Follow a more experienced player, if they are telling you to do something, they probably (i didn't say always *cough* Siddy *cough*) are not trying to ruin your game or trick you. When you are newer following them is without question the best way to go.
If you are on the flank and are near an enemy, there is almost never a reason to build trade ports. just dont do it it doesn't make any sense because if your enemy rushes fleet, you will get smoked.
The best way to get an early game boost is to seize neutral extractors. While it is significantly easier to capture them as Vasari, as there fast moving and cheap scouts can capture them, do not write them off as TEC or Advent as they are significant boosts to your economy.
Using Microing, which is controlling units to be more efficient is extremely important if you wish to succeed in battles. Common microing techniques are every time a ship gets close to dying, phase it out and repair it and send it back, so while you are killing enemy ships, yours are just temporarily away while they repair which pays extreme dividends in the long run.
Using unit counters is also extremely important. LRMS>Light frigs. Heavy cruisers>LRMS. Light frigs are not better then cruisers, but along with bombers are the best way to kill them. Unfortunately there is no real counter to carriers, so what you have to do is make them! Fighters are often the key to success and often determine the outcome of a battle. Make sure you can amass them faster then your enemy as i cannot stress it enough they are the key to victory.
Decided to add some more tips based on some replies
Ok well here is my thought on countering carriers. If it is early game, you could try to spam light frigs, but it is no gurantee he won't have carriers and lrms. There is also no gurantee he will go pure fighters, and bombers do eat up light frigs pretty well, especially in combination vs light frigs. If the enemy is microing his carriers by sending them around the gravity well, then light frigs may not always be the most efficient. The best way to counter carriers without any yourself is to do one of the following three things depending on what race you are.
if you happen to be vasari:
Kortul devastator has an ability called "Jam Weapons" which disables the strikecrafts weapon for a period of time, and is extremely effective to shield your units briefly and have a good portion of his fighter (or bomber) fleet disabled for a period of time
if you happen to be advent:
Halcyon carrier has an ability called "Telekenetic Push" which effectively scrambles the enemies strikecraft as well as dealing physical damage to their hull, which softens them up for flak damage, and keeps them from having a continued assault.
if you happen to be tec:
The Kol Battleship has an ability called "Flak burst" which does physical damage to all strikecraft within a range, again, good for softening up the strikecraft for flak.
Listen, if you are in a pinch and cant afford a capship, then there is no reason that you shouldn't build a few flak. They really can soak up all sorts of damage, are good in a pinch vs lrms, and fighters are extremely weak against them. While they are not as strong as they used to be, do not look upon them as useless.
IMPORTANT MICRO TIP:
if you didn't know already, if you wish to stack commands, simply hold down shift, say you wish to attack ship A, then ship B, then ship C. while holding shift, click attack on ship A, again on ship B, and finally on ship C, the stacking is virtually limitless, and if it has a limit, there is no practical use to filling up the queue.
more could be on the way, i dont know, if you have any requests put them down in the reply box and i will do my best to answer questions
P.S. will have to organize this thread soon if you guys wish me to add more, i know it could be hard to find information as of now.