[CJDG]

Speed comes with working on your endurance.
Derek roddy has an excellent video on working on endurance.
Basically you work on keeping a steady beat and then alternate limbs
first with four hits each side, then 8, 12, and 16... repeat and rinse.
each set is repeated for two minutes.
Then you gradually increase the tempo.

My recommendation is if you have any ritual you are doing right now that has you on a
plateau of drumming then you need to throw something different into the mix. Something
like adding one extra drum in, create some fresh patterns, and then remove the extra drum.
Now try to mimic what you did with the extra drum on just the snare. Experiment with hitting
in different spots, use the hand to mute, set one stick bead on the drum and play that stick
with the other. Move up and down the stick for different sounds. Use the rim. Change the room... go into one with tons of echo and play... sometimes a simple room change can change
the sound of your drums enough to give you new ideas.

Hope some of this helped.