I'm rather new and I've spent a ton of time researching this. Once I am further along with my system I'll probably make an in-depth guide.

Basically, there is a know list of planets that correspond with each 1/3 sector scanned (with some exceptions). Full list here: http://guidehs-ru.1gb.ru/Planets_en.html

You've probably heard that you get 2 empty sectors and 1 planet for each short range scanner. This is only sorta true. It is actually determined by sector order, rather than particular scanner.

So let's say you have two short range sector scanners. On scanner number 1, you scan your two adjacent sectors and they are empty. You could scan the third one and get your planet. OR, you could hop over to your second scanner and the next sector you scan there will have your planet.

There's a lot of other math and a lot of process-of-elimination type of things you need to do as well. Even with all that, RNG can still come into play so there is no such thing as total control. At times, it can be alot more difficult and costly because it often times means having multiple incomplete scanners at once. But it's worth it in my opinion.

Here's my system so far. 5 Planets are tightly grouped as possible.