You don't actually have to tailgate trucks to draft; in fact, maintaining a safe distance from a regular car or SUV has a very noticeable benefit, I've found. Commercial trucks and vans, with their enormous drag, do of course offer a much larger benefit, but you can maintain a safe distance if you want to.

I rarely bother drafting in any form, but if you want to, the best thing to do is to find someone going your desired speed and follow them. Thus you suffer no drawbacks since you still drive your desired speed, and of course you should keep a normal distance from them, but it will help. I've definitely noticed it.