So I recently unlocked the standard Mantis cert.
I’m no expert on how to best use this particular vehicle. Any pro-tips? 
You know, beyond running out in open like an idiot lol
I’d say to try and stay in the open so you don’t get boarded, but not too far from cover so you can hide to get your shields back. I haven’t used the Mantis much, but that’s what worked for me.
1.Stay behind some ground troopers at all times.
2.The mantis has shields, do not take damage when the shields pop.
3.the mantis has 3 modes of Attack: chaingun, 5 barrel rockets, and Melee.
4. Make sure no one gets behind you, 1 board = dead
5. If you get EMP jump out. Your survival odds go up.
The chain gun sucks other than shooting infantry right up on you. Rocket pod spam from a distance is how I managed to get my commendation done with it. The Oni mantis is the only one worth a crap.
Do the rockets home in, or are they straight shots?
On the standard mantis, it doesn’t lock on to spartans.
Dont go right in the action - keep distance
Always, no never, forget to spot check the radar.