I hope no one minds me dropping in some ideas here, i have represented russia in european and world youth meetings, i have a best 100metre time of 10.66, wich granted isnt mind blowing, but i am white and i ran that when i was 16, i would have pursued athletics properly but i made a stupid decision that ruined my chances..Anyway to cut a long story short, i used hill sprints to train, i would jog down and sprint up 5 x over a 150 metre distance, then i would jog for 50 metres and while on the run burst into a sprint, as i ascended the hill, i would do this 8 times, 4 times a week, and mix it in with flat running, never ever use ankle weights, it can do TERRIBLE damage to your shins and knees, and weaken your hamstrings, you can try explosive jumps too, jumping from a box onto the ground then springing straight up as high as you can, this is great for strengthening the fast twitch fibers.
These are my suggestions, and im no expert, but they worked for me.