For tone quality you should definitely work on playing long tones. Like start at G wit no octv. usin a metronome set at 60bpm (or slower when you get used to excercise) play G, G# in minums than A for whole note (4 beats), then go back down to G# , A in minums then to A# for a whole note...do this all the way up to the highest note you can play then right back down to the lowest note & then back up the the middle G where you started. Aim for brilliance on the lower register & fullness in the higher register. For improvement in speed you should practise licks & scales with a metronome increasing the speed once you have mastered it at the speed you begin with. There are some great fast pieces in a Advanced Jazz Etudes by Lennie Neihaus there is also an Intermediate book also...you can play anything you want to faster if you practise using a metronome. Also try playing along with your favorite saxophone players!