Having worked out my strategy I've spent a week implementing it and rather enjoyed it.
It's not for everyone. It's complicated for the sake of being complicated, fiddly and rather time consuming to start with. I'm sure it's not made me anything like as much as the same time spent running level 4 missions would have.
You need to start off by working out roughly what your structure will look like. I went with the layout used in this Eve Uni video: a launchpad with a ring of processors around it near my extractors. They call it a single hub star network.
As explained in the video you need to position yourself near where your resources spawn. So the first thing you need to do is work out, based on your production aims, how much of each resource you will need.
On my Ocean planet I want to produce Test cultures, Fertiliser and Livestock. This will require the following P0 inputs:
Complex organisms (twice)
Micro organisms (twice)
These P0s, when processed, make the P1s that go into the P2s I am trying to make.
I start my scanning by looking for a spot where a good complex organisms spot is near a good micro organisms spot. There are a couple of possibilities so I check the other resources and eventually find a spot where all 4 resources are nearby.
I had an interface issue at this stage. I found it very hard to get the slider in the Scan view to move. It is quite fiddly, just make sure you have your mouse pointer in the rainbow coloured section and you should be able to slide it from left to right. Eventually I worked it out and was able to adjust my scans so that they showed small white peaks for high resource concentrations. You sometimes need to adjust it as you move from one resource to another - if you see a huge swathe of white move the slider to the right to get smaller peaks.
I began my harvesting by putting down 6 extractors: one carbon compounds, two complex organisms, two micro organisms, one aqueous liquids. I didn't worry too much about the varying output - all my extractors are on white peaks so they all produce reasonably well. My best is 1526 and my worst is 1373 which is close enough. If I had had a terribly low spot I might have had to double up one of the weaker ones.
Each extractor is routed to the launchpad and I built up a nice little store of P0 resources a few hours later. It's quite easy to miss a routing so check that everything you expected to see has turned up.
Around my launchpad I placed a basic processor for each P1 product and an advanced processor for each P2 product.
Each Basic processor needed two routes: an outgoing route to the launchpad and an incoming route bringing the P0 resource. I didn't see any way to set this up in advance, I had to wait until I had a stockpile of P0 resources in the launchpad before I could route it to the processor.
So after a few hours I was able to set up my P1 production chains:
Carbon Compounds > Biofuels
Aqueous liquids > Water
Complex organisms > Proteins
Micro organisms > Bacteria
I left it a few more hours then set up my P2 production chains. Each P2 requires 3 routes each. You will later be able to check your P2 processors are working by opening the Routes view and checking it has all 3.
What I found was that where a resource was required by two competing processors once I had routed it to one I was unable to route it to the other processor that needed it since my stockpile had vanished out of my launchpad.
So, as much by luck as by judgment I set up
Proteins and Biofuels > Livestock
Bacteria and Water > Test cultures
The next day I was able to set up
Bacteria and Proteins > Fertilizer
If I had set up the fertilizer first I would have had to wait for both the other two.
My Advanced Command Centre has 17000 MW power grid and I wasn't using it all. After a couple of days I decided to put down another Basic processor as I had stockpiles of some P0 resources built up. That was due to using short duration extraction cycles that produce more and to being a little slow to get the processing started. It was useful in the first week but I'll remove it after I write this post as it isn't doing much now that I've switched to 23 hour cycles.
Your stockpiles are your indicator of whether everything is set up right. If you are stockpiling a p1 or p0 product that should be being processed into something higher you need to check your set up. Click each processor, choose the route window and count the number of routes. Every basic processor should have two routes and every advanced processor should have three routes.
After leaving it a few days to settle down I decided to spend the rest of my grid on this planet. I had enough surplus grid to put down an extra Complex Organisms, an extra carbon compounds extractor. I was just short of the grid I needed to drop an extra processor for another resource in the white spots. However by dropping a processor right near my launchpad and consequently being able to use a very short link I did have enough to drop an extractor in a sub-optimal place. Well better than leaving the grid unused - I set up an aqueous liquid extractor by my base. It produces 1346 per cycle instead of 1524.
I've just turned to the issue of the grid I am freeing up by deleting by extra basic processor. I had 871 grid free. A micro organisms extractor costs 800. 71 grid really isn't a lot to play with. I control clicked my launchpad and moved the link towards my micro organisms spawn. Not enough to get even near the red but even on green it's worth something. I guesstimated 71 grid and plonked my processor down. It's actually 65 grid's worth of link away from the launchpad which is close enough. It produces 883 per cycle, a lot worse than the 1500 I get from most of my extractors but better than nothing.
The stored goods are looking really efficient. The only thing I have in my launchpad are Fertilizer, Test cultures and Livestock. I have no P0s or P1s building up at all! 100% efficiency. 1717 m3 out of 10000m3 room. I also have some storage (500 m3) in my command centre which is not linked to anything.
At some point I will launch my p2s and use them to make p3s on one of my other planets. Looks like it will be a few weeks before I need to worry about that.
So that's my Ocean planet. I also have 4 other planets and in about a month will add a 6th. But you get the idea of my methodology, the same methods but for different resources apply to my set-ups on the other planets. So far I have only done P0 to P2. Eventually I'd like to be producing P4 down there and perhaps even have a POS down there and be manufacturing POS parts.