Air Support Specialist - 5 kills by Air Support->AllowTactician badge to have unlocked secondary of other classes
This is possibly the hardest ribbon to get out there. Basically, drones are meant to distract, not to kill. Just place them where lots of enemies cross and you might just get a kill or two with them. But don't place them too close to a sentry turret, because these fire rockets at your drones.
Assassination Defend Specialist - Stayed alive as Target->More points per Assassination defense
The best way to do this is is to sneak up to the enemy base using a route you know is not defended well enough. You'll just have to play and kill as many as possible to get to the target. Grenades are a miracle.
Body Count Specialist - 10% of kills made overall during a mission->More points per Body Count kill
Just start killing!
Boost Specialist - Perform 10 Boosts->Allow Assault badge to have unlocked secondary of other classes
Every time you have the ability to use boost pills, use them.
C4 Specialist - 5 kills by placed C4 Explosives->Allow 'Saboteur' badge to have unlocked secondary of other classes
Place C4 in hallways during hectic battles, like Search & Destroy. One charge will often be enough, as the enemy will have to pass your team's defenses as well.
Capture and Hold Defend Specialist - 10 points earned while defending a Capture Point->More points per C+H game:
Stay in a friendly capture and hold zone and kill any enemies trying to re-take your position, relatively simple.
Cloak Specialist - Kill 5 enemies while Cloaked->Unlocks Spot and Mark for Scout badge
Very easy, just use your cloaking device and start killing.
Close Combat Specialist - 10 kills by Close Combat Melee->more points per melee kill
This can be tough, as you will have to make 10 kills just knocking people with the back of your gun. It's best to do this in hectic battles. Another tip is to keep melee-ing an enemy spawn grenade as this will tend to kill anyone who spawns in that area as soon as they revive. Hitting campers is also a good idea if you're not going for the headshot specialist badge instead.
Disguise Specialist - Kill 5 enemies while Disguised->Unlocks C4 for Saboteur badge
Disguise and kill. Be careful not to get too close as the enemy's crosshairs will turn red when pointed on you which you give you away. It is advised that you use any chaotic areas on the battlefield to your advantage so that your enemies will notice you less, and are less likely to look at their map and notice that you are not a green dot.
Good Conduct - 0 Team-Kills/Suicides, and at least 20 points->Spawn with more ammo
This shouldn't be that hard. Just try not to kill yourself and your team and collect enough points.
Headshot Specialist - 10 kills by Headshots
For this one I recommend training first. If possible, use the scout class for this. It is easy to disguise yourself using the saboteur class, as you can then follow enemies and easily aim for their heads. Another tip is to find a good camping spot on high ground (room over-looking the "Blood Gratch" canal) and, if possible, shoot stationary targets. Going around a large conflict and getting the enemy from behind also makes for easy headshots, especially when playing as a saboteur.
Healing Specialist - Heal 5 players->Allow Medic badge to have unlocked secondary of other classes
Use your health packs on anyone who doesnt have maximum health (including yourself) and you'll have this in no time.
Repair Specialist - Repair 5 Objects->Allow Engineer badge to have unlocked secondary of other classes
I say use your imagination. Hint: Wrench icons.
Revival Specialist - Successfully Revive 5 players->Unlocks health packs for Medic class
Frequently use the revive-gun. Don't do it when it's inappropriate or intentionally allow players to go down, you'll have some angry players.
Search and Destroy Specialist - 2 Objectives placed/disarmed
Place/Disarm two objectives, easiest is to disarm. Look for games with a limit of less than 20 players to make things easier.
Search and Retrieve Specialist - 2 Objectives delivered
Retrieve two propaganda machines, for this you should find out the spawning spot of these things and get the first, and third one. If you can, find or create a game that requires 5 propaganda flag captures for a win as this gives you more chance of getting more than one flag. Boost is recommended. If using the assault class for boost, pick the grenade launcher as a primary weapon as this encumbers you less than the rocket launchers and allows you to move at the speed of a normal soldier.
Sidearm Specialist - 10 kills by Pistols->Unlocks M4 revolver for all classes
Find a pistols only match, preferable body count only and at least 15 minutes long.
Sniper Specialist - 10 kills by Sniper Rifle->Unlocks 5X zoom on sniper rifle (you do not have to be Scout to get this)
Just use the scout class, cloak, Spot and Mark, and kill. Creating a sniper only match is also a very good idea.
Spawn Point Specialist - 5 players Spawn on Placed Area->Unlocks Air Bots fot Tactician class
This is one ribbon that actually requires you to place the thing somewhere your team thinks it helps. Big games are fastest.
Spot and Mark Specialist - Spot and Mark 5 players->Allow badge to have unlocked secondary of other classes
This is really easy. Just take the scout class and press right on the d-pad until you think you marked enough.
Turret Specialist - 5 kills by Sentry Turret Placed->Unlocks Repair tool for Engineer class
For this you will just have to know where to place these turrets. Read the Engineer section for more help on this.