Some tips, some for Conquest:
If you see me in a room, let me know you're from CAG, so I'm not a prick to you (I'm usually nice anyway).
If you're not great at the game, or haven't played through the campaign, don't play Conquest. Every loss hurts your house. Play Optimatch until you're at least decent, since you won't hurt anything but your personal stats for the month.
If you must play Conquest anyway, play more attacking games than defense. Losing defense games means giving planets to the other team, you literally lose nothing if no one defends. My house has a habit of conquering a lot of planets at night when the good players are on, and giving them all back during the day, when the shit players and 10 year olds are on.
Don't rush at the other team by yourself. Stay with the group, get powered up at the landing pad first, if available. If you take a battle armor and are not good at it, or are good at it but playing against good players, you're useless. If you're good with the tank, and by that I mean good at shooting their legs and tripping them, do that if you can't or won't be a mech. Otherwise, take a mech.
Use cover as much as possible, especially with smaller mechs. Out in the open is not where you want to be. Think as a person, instead of a 100 ton mech. Would you run out into an open field, in a warzone? (The answer is no). Use the terrain to your advantage.
If you don't know how to use the VTOL, don't use the VTOL. You'll kill your team. On every level that uses VTOL's, every team absolutely needs a good one. And that may or may not be you.
Do not kill your teammates. Do not shoot someone if they took the mech you wanted. Do not plant pilot bombs at your own base. Do not stand next to a teammate, or empty mechs in your spawn, when you're about to die. Do not kill your teammates.
Communicate with your teammates. Communication is absolutely essential. A group of average players that communicate well and work well as a team, can beat a team of better players, playing as individuals.
Again, take your lumps in Optimatch if you're still figuring the game out. Don't try Conquest until you're better at the game. Also, hiding behind hills and terrain is not "cheap". Do you expect people to form nice, neat rows and columns, out in the open, like some 18th century Redcoats? Its their job, and your job, to make it as difficult as possible to be killed. Play like your life is on the line. Don't rush out into the open against 4 enemies.