with my students they like to spar at 50%.......keep it not too lite not too heavy.
Ben is right about typically what gets worked the most is sow choys, uppercuts, and chop Choys. They are the most natural to work with.
now, we typically sparr without gloves up to about the 50% mark......if we go heavier then we gear up. i tend to train them more on the San Shou side of things, but we train to fight on the streets as opposed to the ring. My students go clubbin all the time, and almost always get into some type of scrap.
I have them spar one on one, but then i have them spar 3 plus partners. Then another fun drill is placing your hands behind you back since you can't use your hands. you can use your torso to bump or even defend, but typically i encourage them to use nothing but their legs whether its to attack, defend, evade or what ever. they find that drill the funnest one of all. Ill even have the one with his hands behind his back spar two to three people using no hands-all legs.
Hung Sing Boyz, we gottit on lock down
when he's around quick to ground and pound a clown
Bruh we thought you knew better
when it comes to head huntin, ain't no one can do it better