Yes you can still see an improvement in mileage from following larger vehicles, even back at a safe distance.
Also, it may be worth doing some reading on acceleration technique, depending on how slow you are accelerating. By doing a granny start and taking fooooorevvver to get up to speed, you are burning more fuel, for an unnecessarily long time. It may be better to put your foot into it a bit and get up to speed relatively quickly, so you can cruise at speed and get better MPG quicker. You don't want to accelerate hard enough to the point where the computer will go all out and richen the fuel mixture, or to the point where the car delays shifts to run higher rpm (in an automatic transmission vehicle). So if you find that point, back off just a little bit until it shifts normally again.
If you search for it here, it is the idea behind accelerating with (about) 80% load, I've also seen it referred to as "accelerating briskly".
Edit: By the way, I see that it is your first post, welcome to the forum.