I work with the sample and adjust the tempo accordingly.
I'll make chops and play a melody on the pads or whatever I'm doing and then hmm the melody in my head and use tap tempo to get a rough idea then I can adjust to get it right on point.
I find that if I have a set tempo from the get go, I become more refined to it and have to do what I do based on the tempo.
I think you can be more creative when working with the sample first.