I've found that a good power/mass booster for me is building T3 power generators and Mass fabricators, usually 2 power for every mass fab. (or 3 for every 2?)
Another great thing I have been introduced to is using support commanders as mobile generators. Just give them the resource upgrade and watch your economy soar. Plus they don't take up nearly as much room as all those power and mass fabricators would.
Who do you usually play as?
I like to build defensive lines of many (10-20) PDs and some T2 artilliary. As the AI seems to over-protect against air units, I would not suggest putting too many resources into that kind of attack. (of course a couple soul rippers or a crapload of UEF T3 gunships can lay waste to most opponents)
Hopefully that helps some.