I'll usually use up my available supply and then go ahead and research shield health and armor upgrades as high as I can go with the amount of military labs I have. That's if I haven't started fighting my opponent yet. i'm always scouting though and keeping an eye on his fleet size, and if it looks like I need more ship to take him on, I'll go ahead and upgrade it. Also I find if Im weak on metal or crystal, I'll try and purchase the extraction upgrades as high as I can before purchasing the fleet supply upgrade.
Scouting is important.However to be really good you need to look at some math when playing the game.Always get tier 1 health and sheild upgrades.They are always worth it.Consider what your getting for what your spending.Javs for instance.If your fleet is mainly javs then they have low hull points.Hull upgrades wont be as good.You get 5% per upgrade.How much will this add to your overall fleet hp?It may be better to buy more ships.For instance.A jav hull is 500.5% of that is 25.So you will need at least 20 just to add 1 jav worth of hull points.Thats not including shield points.I think 1 jav is 1/3 the cost or cheaper than the 2nd hull research.So if you have 20 javs do you up it to add 1 hull worth and no dps or buy 3 more javs and add more dps?To add in the shields you would need 30.Its the same with most all research.
When buying fleet point there is things to consider.How big is your enemies fleet and how close?What are your defensive capabilities and do you want to play defens or offense.There are tipping scales in this game.Someone that goes eco will be vulnerable until his eco is going good AND HE BUILDS A FLEET.Your window of oppurtunity is short and you must strike hard and fast to cripple his war machhine before it rolls you over.
All the resource in the world will not kill a large fleet.If your enemy has 60 lrf and 2-3 caps and you have 2 caps and a handful of lrf you are dead.You will lose that planet and at least 1 more.He is killing all the money you invested.Most likely even if your eco is 80 you have lost everything.Depending on how many planets you have.
Timing takes experience.Eco till the last second and then throw up 2-3 factories and pump them out before enemy comes poundin.Build a fleet equal to his in a fraction of the time it took him with your supirior eco.If you can time it you can invest at a lower tax rate than him then fleet up at last second.You will have equal fleet with much larger eco to overwhelm him.You continue to build out of multiple factories while he can only build 1 at a time.
Consider how much your eco will drop?Will you be able to feed your fleet after it drops?Feeding your fleet should match your eco with respects.Dont have large sums of money lying around.Sink it in eco or research or fleet.If your eco is well off to produce ships from 1 factory continuously and throw down a trade port 1 after other then your close.If your on frontline this is almost a minumum production rate to defend yourself.Atleast to the 3rd tier of supply.
Alot come down to you should buy next level if you can support it.Sometimes on frontline you are being fed and have no choice but to reduce your income to dust just to survive.Many situations compete for your chices.It can be a taxing game that win or lose by your choice.