hold on to something (like a lamppost or high wall) and bounce on one foot for a while, see how high you can get.
Hop on one foot. There's a lot of debate on whether springs do soften up over time, but i found these techniques helped me!
Also, what rating of spring did you get and what weight are you (if i can ask that!) as this can affect height e.g. if you got an 'over' rated spring it will take you longer to acheive maximum bounce.
Also if doing double foot hoping, do a run up and launch off one foot, see if that helps.
HTH