
My first thought is . . .
Any brew style done while peacefully listening to Kenny G and his sax in the background... (Okay, so that is a bit corny)
My second, and more serious thought is . . .
To ask what you meant by smooth. Both cold brew and French press have a silky body mouthfeel and can lead to what most would describe as a smooth cup.
I think any brew method where you are using the appropriate coffee to water ratio and the correct water temp can produce a wonderfully smooth cup. My go-to favorite is using a pour-over method. My starting recipe is a 16:1 water to coffee ratio brewed with 200 degree F filtered water.
Time to throw on the lab coat again & experiment with the ratios and prices you like!