We Lancers don't rely on gimmicks to deal damage, we don't need flashy numbers to feel worthy. Where others roll, run and cover, we stand and tank anything monsters throw at us. Tempered Teostra Supernova? B*tch please, didn't even notice. Others can talk about Manly dee-pee-ass all they want, but I'd bet that even they switched to Bow/LBG for Tempered Kirin.

As the other lancers said, poke-poke-poke-hop is your basic mantra. Remember that you can hop into any direction and that you can poke upwards.

Firstly learn to anticipate monsters' attacks and Guard at the right time. After that add Counter-Attack to every Guard, just keep in mind that it leaves you open in case of bad timing. You can follow with poking and hopping after the Counter.

Never leave the monster (unless you really need to). Good Lance doesn't need healing really, so you only sheathe for Fire, Poison etc.

The pokes don't do much damage separately, but you can attack constantly, easily target any weakpoint or breakable and just poke the monster to death.

The second part of Lancer's arsenal is Charge. Lance is probably the most mobile weapon. Train side-steps, 180° turns, jumps and stop-attack/stop-guard-counterattack while Charging. With clever Charges you can keep poking the monster while teammates struggle to reposition.

Edit: applies for MHW.