Drones are arguably the coolest feature of FFOW, and can take some getting used to since there isnt really anything to compare them to from other games. This is how ive been using them, but feel free to add your own tips.
When using drones as either faction, the first thing you need to think about is where you will position yourself while you are driving your drone. Since you are unable to defend your body, nor see anything around your body, you are very much exposed. Try to place yourself on a corner around an alleyway, behind some cover, or anywhere where the enemy will find it difficult to find or kill you. Squad members should try to protect the drone user as well. Deploying a drone in the middle of a firefight is a great way to get yourself killed.
The drone role will likely be a favorite among many SLs because it allows you to add significant firepower without putting yourself and your spawn point in jeopardy. The downside is that you cannot have an ever shifting spawn point (which may be hard to do regardless since this game is all about frontlines), and you could be exposed if the enemy flanks you. If a SL uses drones, it will be very important for him to position himself correctly, have his squad members protect a flank and the drone, and to lead from the POV of the drone. Also, having a squad member with the repair ability will come in very handy, as they can very quickly repair any drone to full health, cutting down on the amount of re-deploys that can cost precious time.
It will also be important to become efficient with drones. You can press right mouse to keep the drone where it was last, and either fight normally or use another drone. Selecting the drone again will allow you to pick up where you left it. Keeping the drones hidden and around corners will help keep them stay alive and forward, and having your squad members spot enemies so that you can use the correct drone will help a lot. Finally, pressing space bar will allow you to switch from 3rd person to 1st person point of view.
Both factions have different drones, so here's how I've been using them.
Red Star Alliance:
Tier 1, Tiger Eye Recon Drone:
Note that the recon drones are the only drones that are deployable while prone, which can help in keeping your body safe. When the recon drone comes close enough to enemys, it will put a red square around them similar to a BF2 UAV. This will then transmit these enemy positions onto every teammates map allowing them to fight much more effectively. While it is airborne, if you press right mouse the UAV will remain stationary and continue to monitor enemy activity while allowing the person to fight normally without having to control the drone. If you can hide the drone in a good spot, then its possible to have constant UAV information while still fighting or using another drone. If crap hits the fan, or youve gained enough intelligence from the drone, you can fly it into an enemy, left mouse click, and hopefully kill the target. The blast radius is fairly small, so its main use will be surveillance.
Tier 2, Tiger Runner Assault Drone:
This is basically a very small, fast, track-based drone that explodes on detonation by left clicking. The explosion is significantly bigger than the recon drone's, so you can be slightly farther away and still kill people. You can use it in many different styles. The most effective will be ambush. Simply hide it behind some rubble, or around a corner, and wait for an enemy to pass before detonating. This can seriously hamper an enemy assault, especially if you can follow it up with an infantry push. Another way is to use its speed and low profile to maneuver around and into enemy forces. Either way you use it, its certainly a shock weapon that will be best supported by an infantry push afterward.
Tier 3, Tiger Claw Attack Drone:
I feel this drone is fairly underpowered, especially considering its a T3 drone. It flys similarly to the recon drone, but is capable of shooting rockets. The rockets have a very small area of damage, and are extremely inaccurate. So far Ive been unable to find a common deviation for the rockets, so this will certainly take a lot of practice to master. It will generally be used to support an offense in conjunction with infantry, since its a very hard hitting attack drone.
Western Coalition:
Tier 1, Hunter Recon Drone:
There really is no practical difference from either recon drones aside from their looks. Use this exactly the same way as the other recon drone.
Tier 2, Assault Drone:
This is my favorite drone. Its a track-based, tank like drone with a machine gun fitted onto it. It has several 50 round clips, but a rather long reload that can leave it a sitting duck. This is a very hard hitting drone that is great for supporting both offense and defense, and against another human will almost always win because its armor is fairly significant. Its best used on point with infantry supporting it. The drone can take some fire, and cause enemies to spread out making it easier for friendlies to kill.
Tier 3, Mortar Drone:
Another track-based drone, but instead of a machine gun it has a mortar with several 4 round clips. The explosion radius on each mortar is decent, but you will have to hit pretty close to a targets feet to register a kill. Hitting several mortars near an enemy will also likely kill it. This drone takes a lot more skill than the assault drone since the mortar fires along a curve, but it can effectively shoot over cover and force enemies to either re-position themselves or to sit and die. Although effective at range, its just as effective at close range.
Drone Counters:
Using drones is one thing, but killing them is important too. Recon drones have very light armor, but can sometimes be difficult to kill. Keep your eyes peeled for them, and only a few shots will down them. They also make a distinct buzzing sound, so keep your volume up lest you 'splode. The attack heli also has fairly light armor, but can be difficult to actually hit.
The C4 drone is difficult to kill, but it doesnt have a lot of armor. Keep an eye open for them, and be accurate. They also make a distinct RC car-ish sound.
The assault and mortar drones have fairly thick armor, so its simply going to take a lot of firepower to down one. They are easy to hit and see, but remember that theyll likely be supported. Using cover will be important. Take pot shots, and before you take enough fire to die, drop into cover again.