Investigation Crew Skill Guide
The only way to raise your mission crew skills is by... You guessed it! Doing missions. Missions require nothing on your part besides a few simple mouse clicks (and some credits) and are extremely rewarding. And since Investigation is a Mission Crew Skill there is no other option for increasing it. To raise your Investigation you will want to focus primarily on the Companion Item missions. The Companion Item missions take half the time to do of the other missions. Take a look at this picture to see the difference.
Notice how the Companion Gifts takes exactly half the time? This is the same all the way up to 400 so hop on board the Companion Gifts train!
Crew Skills That Go Well With Investigation
Investigation Leveling 1 - 100
For the first 100 levels of Investigation you will want to run all Rank 1 missions up until Rank 2 missions become unlocked around skill level 60. This bracket will take about an hour to do if you have 5 Companions running missions for you all with high affection levels. It's also strongly recommended that you choose the missions that take the least amount of time. For every Gathering/Mission Tradeskill there are missions that take two different sets of time. There are six missions for each level bracket, one will take twice as long as the other.
When it comes to just leveling professions as quickly as possible you will want to always pick the shorter missions. If you have 5 Companions then pick 3 of the shorter missions from the highest rank mission bracket you have unlocked and 2 from the rank just under. This will maximize the time spent and give you the most skill points for least time spent.
As for what to do with all of the companion items you recieve through Underworld Trading; I recommend feeding them to your companion. To see a giant list of what each companion likes click here.
Time Required To Level: An hour to an hour and a half
Investigation Leveling 100 - 200
At the very start of this bracket you will want to run short-timed Rank 2 missions and an occasional Rank 1 mission that is still yellow or red (meaning it will give a skill up). Starting around 120 you will unlock some Rank 3 missions which you will want to run for pretty much this entire bracket. When you first unlock the Rank 3 missions start by running all of the ones available to you while mixing them with the Rank 2 missions that still reward skill ups. By about 150 to 160 you will be running mostly all Rank 3 missions (even the ones that take longer to run, because at this point Rank 4 missions aren't available and Rank 2 missions are all grey.
Once your skill reaches 190 you will unlock the Rank 4 missions. You should know what to do by now, keep running high Rank 3 missions and the low Rank 4 missions to maximize time/money spent. You won't have to worry about running the very long Rank 4 missions until about 240/250, that's when most of the Rank 3 missions go gray.
Time Required To Level: Two hours
Investigation Leveling 200 - 300
Most of this bracket will be spent leveling your crew skill through the Rank 4 missions which continue through this bracket all the way up until about 270. Once your skill reaches 270 you will unlock Rank 5 missions, which start to reward you with a ton of very good selling items. For all mission Crew Skills Rank 5 missions are the first set of missions that will reward you with Rank 5 Companion Gifts. Granted most of them are green for this bracket and not blue or epic, the point is that they still grant your companions affection!
As always for this entire bracket focus on the missions that don't take a lot of time to do. The missions that take 13 minutes will be the main ones you want to run, ignore the 20 minute missions until you have absolutely no choice anymore. Once you unlock the Rank 5 missions around 270 skill level you will want to run a mixture of Rank 4 and Rank 5 missions to maximize your chance at a skill up. You could actually stay with Rank 4 missions for a little bit longer if you wanted too as they take half the time of the next rank's slowest missions.
Once you reach 300 it's onto the home stretch!
Time Required To Level: Four to Five Hours
Investigation Leveling 300 - 400
For the very start of this bracket you will be running Rank 5 missions up until you reach 320. At 320 Rank 6 missions will finally unlock for you, which once you can start running Rank 6 missions you will want to run whatever is available in this bracket. Whatever items you get from Rank 6 missions that you can't use, SELL! These materials sell for a ton right now since they are endgame materials and are in extremely high demand. By selling all of the Rank 5 and 6 materials on the Auction House you can make back almost every single Credit spent to raise your crew skill!
As you could have guessed Rank 6 missions take a really long time to level up from doing. Each of the shorter missions you can expect to take 30 minutes each and the longer ones take an hour to do! With max affection the hour long missions only take 53 minutes instead of an hour and 3 minutes or whatever, but it's still a really long time to wait! If you would rather collect other materials while also leveling this Crew Skill than you should only be running the 30 minute missions instead of any of the hour long missions.
Time Required: 15 - 20 Hours