Another thing to work towards is to internally minimize the distance between the nadir and apex of your slurs. I phrased it this way to include flexibility studies and glisses as well as slurs between two botes.
Conceptually, when you start you will experience the distance between the harmonic series as large. These can be diminished over time. When I perform slurs, I try to minimize the distance between the notes so to speak, which also helps keep me playing down on the notes as I ascend and up on them when I descend.