My first time i felt like how you feel when you're the perfect amount of tipsy. I lost inhibitions and i felt relaxed and a little euphoric. That was the first hit or any hit after a long break.
Regular smoking was more like, every time i smoked i felt more relaxed and more awake. It was like a little energy boost. You can't quite place when or what exactly happens, you just feel better and ready to go after you're done.
I have since quit smoking and a decade later i still miss it. Smoking was the perfect work pause, because it forced me to go outside and think. It also gave me a little jolt of energy and it was perfect for creative thought. I haven't quite managed to find the replacement for it, but the best I've managed was periodic walks with a notebook during work time and coffee. Also drinking water.
Smoking is terrible for your health and even though i miss it, i don't regret my decision to quit.