Ok so before you ask, yes I have a life (just not this past week.) Yes I am deprived of sleep. I haven't slept for more 7 hours TOTAL the past 5 days.
I am now done with the launch week grind.

Ok so here are some good tips

1. Play Cranked (Obvious Tip)
2. Optional tip: Play with a full party on strikezone every game. (Just keep backing out of each lobby until you get stikezone with a full party
3. Work on your operations!!! I know it seems like forever to complete but it's worth it in the long run
4. Run a shotgun if you play on strikezone. I prefer the bulldog, but any shotgun is fine
5. You need to work on your gun challenges
Number five is important because not many people know that you can 5000 xp for completing gun challenges. Most people stop at 2500 xp.

2000 kills with any gun= 5000 xp
300 kills with no attachments= 5000 xp
200 assists with any gun = 5000 xp
300 kills while crouched = 5000 xp
100 rescue kills = 5000 xp
Etc. Etc.

In the long run this kind of xp will be amazing.

6. If you have the money, buy monster drinks with CoD: codes on them. You might unlock double xp
7. Run Specialist. If you run specialist you will earn more xp per kill when you earn a perk or achieve specialist bonus.
8. Be wise about choosing you gunfights. Don't try to get into every gunfight possible. Try flanking, dropshotting, jumping, etc. You know you want to try hard for xp.
9. Field Orders
10: Wins at high levels equals better match bonus.
11: When playing Cranked never run to the middle of the map. Play around the outskirts. (Running blindly and dying will make you want to snap your install disk for this game in half.)
12: Don't waste time in a game.
I know there are more ways to level but here are some of my ways.

Now time to sleep like a baby.