So I heard that there is a certain way you can twist your string so that your yoyo sleeps longer. How do you do it?
best ways to sleep longer are harder throw, more centered throw, and a decent bearing, however the first two are more important… however the twist of the string affects how a yoyo spins in negligible 
[but generally I think a tighter twist {but still no tension} is better]
good luck 
Ya I know what you’re talking about. It’s not what you think it is though.
What you do is throw a strong sleeper and then grab the string at the very bottom, right next to the yoyo. Then you twist it left or right and the yoyo will respond by turning. What this is used for is keeping the string off the side walls.
sleepers! just stop your sleepin’! 'cause it won’t be too long.
It’s only useful if you’re going for a sleep record (yawn). Has no effect when doing tricks.
while the yoyo is sleeping you can twist the string tighter or looser from the bottom controlling which way the yoyo tilts and therefore not making it tip over and stop spinning. :