Rough steps:
1) You need the entire map scoutedIf you haven't unlocked Scout II at least, this could be very difficult. You need to find all the CSGs (Core Shield Generators), everything that reduces AIP, and the AI Homeworlds. If you are having trouble getting Scouts out there, suicide Mark I Missile Frigates into systems to kill all the Tachyon Guardians. This takes a little time, and builds up some threat, so don't bother with systems unless you are having trouble getting scouts out in that direction. Basically, for each system you kill all the Tachyon Guardians in, your Scouts can get about one hop further.
You just need to peek into each system to find what you need. Don't worry about keeping a scout alive in the system. You need information, not pickets. If the AI has an unlocked ship type with Tachyon Beams (Sentinel Frigates for example) scouting will be much tougher. You'll probably need to resort to Transports to get your scouts a one or two system head start.
Send scouts grouped by Mark. Sending Mark I and II together doesn't work well. Pull your scout pickets off adjacent systems so you can send a bigger mob. Basically, if you can trivially replace a picket, pull it out until you've finished your scouting. You can also send a Scout Starship with your Scouts to get them further. Make sure to Group-Move them in that case. This is especially useful if the AI has Sentinel Frigates or Snipers, as the Scout Starship will protect your Scouts from sniper fire.
On most maps with 60-80 systems and up, unlocking Scout IIIs is very helpful to make this process go faster.
2) You want to raid every AIP reducer you canGet any Data Centers can find when you get a chance, but do all 4 Co-Processors very close together (raid in toughest to easiest to reach order). It is ideal to do the Co-Processors after the Data Centers generally, unless you've already killed one or more Co-Processors.
For these raids, use Raid Starships. Put all 3 in a Transport and micro them on suicide missions if needed. On Data Centers that are only a few hops out, use a Transport with Mark I Bombers to save you the time of rebuilding the Raid Starships. Don't waste your Raid Starships. If they are suiciding, after taking out the Data Center, consider using their last few moments alive to knock out Ion Cannons.
3) If you find a Super Terminal, it may be worth it to useThere is only one Super Terminal, and not every map has one. If you do find one, and you haven't done a lot of hacking, this can be a very good option to knock off 50-100 or so AIP. Without additional information I'll skip the details of how to go about this.
4) Plan out the CSG systems you need to takeYou need to figure out which systems you will take to knock out the CSG networks. You need one each of B, C, D and E. You need to take 4 of the 5 in the A network. Look at each planet and make your determinations based on what you get from it and where it is located. Ideally, you want to be able to use these systems as stepping stones to the AI homeworlds. That means you need to be able to get within four systems of both homeworlds with what you select. The CSG-A networks are always on ARS planets, so you might want to try and sneak a Science Lab II (it has cloaking) in and see what ship would get unlocked (look on the ARS tab, the left-most ship is the default unlock).
5) Clear a pathYou need to start clearing a path to homeworld. This means clearing systems of everything except the AI Command Stations and anything else they have that would give AIP if killed. Try and avoid picking a path that involves a Black Hole Machine, because you have no choice but to incur AIP going through such a system (you need to either kill the BHM or claim the system, both give you AIP). If you have enough firepower to kill Wormhole Guard Posts quickly, consider knocking them out too, but only on the wormholes that are part of the path you are taking to the homeworlds. Basically, you want nothing spawning in the sytem (except the Command Station) that will be in range of a convoy travelling to destroy their homeworld.
?) Set up a cheese choke pointOk, you have a Grav Driller AI. If I recall, his Gravity Drills are capturable. By taking one of his systems and setting up your choke with the Grav Drill intact, you can create a near-invulnerable choke point. Here is an
example of one I set up in an 8/8 game. The second and third picture show the layout.
Once you get all that done, you should be ready to knock out the CSGs and then drop the home worlds.