1-when you've finished using the spraycan, turn it upside down and spray on a wood plank or something else (and always use the same, don't throw it aways, it becomes a tools...)... that way you keep the nozzle clean...
2-storing your praycans: keep them upside down, that way you're sure the the propelling gas inside won't leak out of the can (that plastic cap is more for protecting the nozzle then keeping the propelling gas inside...)
3-when you have a blocked nozzle, remove it and soak it in hot water for ±15minutes before brushing it with a toothbrush...
4-if you really have to get a pin inside, use a really small needle... but if you're beginning on that path, be carefull not to damage the nozzle.
5-ALWAYS FOLLOW TIPS #1- & #2-, You'll be saving $ and won't be waisting any material. better for you and the environment...
Marlec