Good choice to get RT .
My big tip is suppresion fire. The day i worked out that scouting and suppression fire were the keys to succeding in battles was a great day.
By that i mean when an enemy unit is spotted, plant some area fire all over it with units that may not be able to see it clearly, but can see the area in general. This will suppress the enemy unit and enable you to get to it and kill it, or it may even actually take out the enemy unit
Scouting and suppression fire FTW
Also, I use Fire Briefly a lot ( I have it mapped to a very easy to find key ) Then I allocate area fire 'briefly' and hit the key three or four times. This will give you fire for 30,45,or 60 seconds. it means that you can then forget about that unit and not have to "turn off" the fire command, because it will automatically turn off.
After the turn cycle, re-evaluate which units need to be laying down fire and repeat