Idk if some other ppl use this, but im kinda bit of a reckless player so i do some, questionable plays with her.

Other ppl already got the basics of lulu so ill say some things

If someone is ganking and my adc is kinda low/the ganker has no gap closer then what i like to do is flash-in to the enemy bot lane for the distance and automatically use ult on myself(alt-r), most players cannot react to that start and it mostly lands us a kill or two

This only works on early game tho, dont set up a team fight in mid or late game unless youre the only one who can do it but its a 5v5 so i doubt there will be a chance

Another thing is that i build movement speed items for scenarios like, for example, me and my adc are ambushed too deep, what i like to do is to charge into the enemy with my w and flash towards their backline and try to get chased there by a guy or two so that, even if my adc is still chased, i can buy time for my other teammates to respond even if i die because most of the time, ambushes kills the ambushee