I tend to take one of two strategies, with a variety of tactical or strategic branches, depending on the specific situation and technologies involved [note, I always consider putting the homeworld on perm alert too risky]:
1) Take the world next to the core world [put the core world on alert]:
Pros:
*Transports arrive at AI homeworld with minimal damage (1 hop damage). This allows escape via transport if necessary.
*Manual retreat is possible, through enemy core world, if it should become necessary
*It is possible to quickly reinforce your position if necessary.
*Can potentially create a 'beachhead' in the core world area to keep the wormhole clean and/or help neuter the plant if that is your plan.
*Easier to get warheads through to the AI homeworld alive (if it is your intention to use nukes etc.)
Cons:
Mil station:
*Puts core world on alert, practically forcing you to neuter it to allow for effective attack/retreat path.
*Neutering process puts homeworld on (temporary) alert while you neuter it, causing significant reinforcement.
*Special forces may show up to defend core world, dragging out battle longer and putting homeworld on alert for even longer.
*Depending upon map layout, this can put MANY core worlds on alert all at once (I think I put 3 core worlds on alert once, doing this. This is very bad if ships start overflowing into carriers, even if you neuter a single core world as a path to the homeworld.)
Jammer station:
*Vulnerable to free-threat killing the station
*Losing jammed-world is serious blow, now putting core world on alert. By the time you recover the Jammer station, the damage has already been done typically, and it is often now useful to instead rebuild as a mil3.
Both:
*Threat can 'hang out' on the Mk V world, waiting to come into your station, making passing through or accomplishing neuter goals that much more difficult.
2) Take the world one hop out from the coreworld
Pros:
*Core world and homeworld are never on alert unless you are there with a fleet that very second. This means they will only reinforce when you attack, and freed threat will immediately leave the systems (once you are gone) to search for softer targets.
*Station type doesn't really matter for the taken world, in so far as you don't need to take special consideration as to putting any core or homeworld on alert, and may just be facing standard planets.
Cons:
*Any attacks are one-way trips. If using transports, you will make 2 out-of-supply jumps, trying to get back to your space would constitute a 3rd out of supply jump, destroying your transports. The amount of enemy territory you'd need to go through also makes manual 'walking' retreats a disaster.
Each method has it's pluses and minuses. If I have the resources, flows, spare fleet and time to slug it out in a longer battle, I'll usually take the planet next to the core, mil 3 it up, neuter the core world, then whittle the homeworld bit by bit.
If I'm looking for a faster strike with more limited time/resources, or if my fleet is needed elsewhere mots of the time, I'll probably take the 3rd world out (or one next to the core and jam it), prepare small, surgical, suicide strikes against the guard stations, and then confront the strategic reserve and home command station with the main force as the 'final grand battle.' after eliminating all the guard posts with very minimal losses.
So a lot will also depend on your strategic situation.
