I saw someone asking for event tips before and I don't know if this counts as a tip but here is what I always do (and it helps a lot):

Start playing as soon as the event start!!! Save your commercial boosts for it too so you can play more! Why? Because when the event is starting, your ranking won't be 10.000 or something, you'll be around 100-1.000. Play more than once at day, so this way you'll keep a certain ranking margin (?). If you have Boost Drinks, save it for the final day so you can boost your points (sorry, it wasn't propositional)!! Oh, I use 2 boost lives for one song (some people might think it's a waste, it's up to you what you wanna do).

I thought this was a common thing to do, but I told my friend, who said that she never thought about it. Then, I remembered this person on Banpa, so here am I. I really hope this helps someone, and I don't really know if it's a good strategy but it works for me so I wanted to share it.