Well, you only have three or four options. #1) If your Base Production is 1 or less, terraform. This has a chance of making things worse for you. If you have -2, go for it - it can't get worse. If you have -1, then, assuming you have an even chance of getting anything from -2 to +2, you've got an 80% chance of improving or staying the same, or a 60% chance of better. Good odds, especially considering you could get +3 PM overall out of it! If you have 0, then that's a 60% chance of improving or staying the same, or a 40% chance of better. If you have 1, then that's a 40% chance of improving or staying the same... but only a 20% chance of actually improving... so unless you're willing to give it a few tries, at 1 is decent enough. If you have 2, then you can't get better through terraforming.
#2) Industry Style / Pollution You need to balance your industry style and pollution. First of all, lowering Pollution will increase your overall Production Modifier, for non-URO miners, so this is a good thing. Here's a quick summary: LF - This is really good, in theory: +5 PM, +3 Pollution. The +3 Pollution means that, after a few turns, your Pollution will end up two or three points higher than it was before, so you're trading +5 for -3, or an overall gain of +2. This is decent. However, for each LF neighbour you have, you're getting +1 Pollution, so if two neighbours are LF as well, you're only breaking even. N - This is decent. Just add up the G neighbours and subtract the LF neighbours, and that's your Pollution modifier. If it is positive, you're worse off than G, generally. If it's negative, great! That means your Pollution will go down - but this doesn't really raise your PM if your pollution is already at 0... so what you have to do to be efficient is to make the most of the lowered pollution, and refine/manufacture! If you have -3 Pollution overall from this, then you can afford to refine two times AND have an Academy, with no PM loss! G - This is overall net gain of 0, so use it if you have too many LF neighbours, or you don't want to have to bother keeping an eye on your neighbour's production styles (or if you really need to keep your pollution down due to hoping to farm)... -2 PM, -2 Pollution. Remember what I said about N, though - you need to pollute in order to take advantage of the -2 Pollution, so it doesn't really improve your PM score, but just lets you do more without actually affecting it. Also in this category are the energy buildings: Windmill and Solar Panel. Each help considerably, as they let you do even more without pollution!
#3) Government. Monarchy is best. You get an instant +3, so long as you have at least three Outposts... Plus an additional +1 for each vassal you happen to have. Mind you, if you're going to vassalize people, Fascism might be better. Technocracy is -1, so avoid that unless you really want to keep your reactor... Capitalism and Bureaucracy are +2 (former only requires Office Tower, latter requires Office Tower and Customs House). Fascism is also +2, but only if they're hosing no outposts... so the only way to really take advantage of this is to close your borders and go on an attacking spree, but in that case you might as well go with Monarchy. This is likely just a special perk for if you already want to be an agressive nation...
#4) Diamond Drills. Get lots of them, as they're +2 each. Sweeet.
And that's about all you can do. ^____^
Is everything I said correct? D: Anyone have any other ideas?
I think the best way is getting ahold of Diamond Drills, personally, so long as you can protect yourself from nuclear attack (ie keep some EUR and ICBMs handy, so people are reluctant to attack you themselves).
Best way to get +10 PM? Be Monarchy with LF industry style, since that's +8, and have a land production of 1 or 2 (if 1, it'll have to be Sunny, and either way you'll need 1 DDRL if you want to keep +10 even during rainy weather)... of course, you'll have to be a URO miner, since your pollution will be at least +3 even without neighbours contributing via being LF or spill...