That. Is. Awesome! Isn’t it cool to see improvements happen through practice? This evening I was practicing a new frontstyle trick: split bottom mount with a miss on my throw hand index finger to get those cool spins like in the Kowalski video I posted and I found myself pinching off a bunch of string to create a lot of slack (?) so I could get 5-8 big and good spins and I was like “what did I just DO?” That was cool and not premeditated! Now I incorporated that pinching of the string and creating a lot of slack string when doing tricks, mounts and binds and I was thinking “is that cheating?” but it’s not, because unless I purposely use my yoyo to injure someone, everything I do with my yoyo is fair game and I, WE, can incorporate any move or technique we want at any time and no one can say “that is wrong, get with the program!” With throwing we all have a freedom to do as we please which is a rarity in pretty much all other areas of our lives or maybe I am just romantasizing yoyoing.
Love this comment. It is true - no matter how long you throw when you learn a new trick - it still is the same. An amazingly satisfying feeling. 
A few random considerations>
Realize that if your yoyo is tilting just enough for the string to touch a side of the yoyo; the drag can affect spin time.
Also the string you are using may not jive with your setup. Too fat or too rough(creating drag) or possibly too slippery in relation with your response system? In other words; you can power up your throw; but if the string slips somewhat in the gap on the roll down; your spin power is partly lost.
It was suggested to use a longer string. Good in theory. A possible problem I have noticed over the years is often; when a person is using a longer string; they alter their power stroke because of a fear of slamming their yoyo into the ground. Tweaking their stroke may overcompensate for the string length and can cancel the longer string potential spin advantage.
Words of wisdom. Words of wisdom. Thank you.