That asari ally ach is a bitch to get, congrats on that!
How do you remember where you've been and what you've collected on each planet?
Jav, what I do, is I try to do what you were
attempting to do, which is clear out a system at a time. For instance I woudl go to the horse head nebula, then try to tackle every planet on each system within the nebula before leaving. This is not always possible but it's a great way to avoid duplicative efforts.
Other than that, when you enter a system...you know what... this is a great time to clarify definitions:
A
planet is the smallest unit in the game. You can land on these. A
system is a star, that has several planets revolving around it. What is the thing called that has all the systems in them? For instance Hades Gamma is a ______.
So what I was trying to say is when you enter a
system, work your way from the inside out, or outside in. Take the local system or whatever it is called. It has Pluto on the outside and Mars in the inside. Start at Mars or Pluto and work your way out or in respectively. THis allows you to avoid what would amount to probably an hour or two, of double checking planets you've already checked. Some have minerals, others have wrtings, and about half have nothign at all.
Constantly knowing that you have a system in place will prevent you from having to take the time to re-check a planet you can't remember if you checked or not. After landing on earth's moon, I could come back to the Normandy, and confidently know that I only needed to check the planets that orbited the sun INSIDE of earth, because I always, without exception, work my way from the outside in.
Its sort of a nitpicky tip but it will save you some time.
Other than that you really need to get those electronics adn decryption skills leveled up. Nothing sucks worse than being on a planet you know you'll need to return to once you get your elec/decrypt skills leveled up. Okay playing for forty minutes without saving and having to start ALL over sucks worse but it is annoying not being able to open things. The exp is valuable and so is the loot!
how do you know if you've found everything on a planet? It takes quite a bit of time to patrol the surface.
Yeah it does, and mineral deposits are the only thing that don't show on your map (though they do appear on your compass. I jsut took wide swaths in the mako (the compass really does cover almost a third of the width of a map, so you don't actually have ot drive into corners). Know though, that they give you 4-6 extra out of 20. So if you need to find 20 rare earths, and you found every sinlge one ther is to find, you may end up with 24 or 26/20. They give you extra so I sort of said

it to scouring every sinlgle inch of each uncharted planet.