The smoothest way to smoke a water pipe, it always choose the decent bong with better peculator like the one with arm tree or matrix filter, they will at lease 80% increase the water filtration and make you inhale so much smoother.
I've ever tried has without a doubt been the Volcano, originally invented as a way to treat cancer patients with high doses of medical marijuana as a painkiller. The Volcano is a device that heats weed up to a point where THC is released, so you still get high, but without burning it, so your lungs won't suffer. Once sufficiently heated, a massive plastic bag (sort of like a balloon) is attached and the vapour is released into the bag. Once the bag is full, you detach it from the base and replace it with a mouthpiece. Inhaling by pressing down the mouthpiece to allow airflow lets the vapour into your lungs.
I always cough when smoking weed. I've always had bad lungs, and smoking weed is certainly not helpful, but even when I cough with the Volcano (which is often because it's so strong) it feels way smoother and cleaner than anything else I've tried. It's very convenient for smoking inside without too much smell as the bag traps the vapour and after inhaling, you can simply exhale out of a window. The only drawback to this method is that you have to hold the vapour in your lungs for at least 10 seconds to achieve the full effect.
Overall, the volcano is the best device I've ever used to ingest marijuana and it also gets me the most high. Whereas joints and bongs give you 20 to 50% of the THC in the weed, the volcano gives you 90%. This means that less weed is needed to get the same high effects, and in addition to saving money, you aren't inhaling smoke into your lungs which will make it so smooth.