I just bought my first pair of Sennheiser headphones, is there anything I need to know?

I got the Momentum 4's and I saw a previous post mentioning something about the BTD 600? I already have Bluetooth on my PC so I'm not sure if I require that for the best audio quality. I'm using the headphones for gaming and music.

So far I've already disabled the "Handsfree Telephony" option in Windows and the sound quality is so much better.

I just wanna make sure I'm not missing anything to get the most out of these headphones. TIA!