Hi everyone, this is my guide on leveling up fast on MW3. Myself i am currently prestige 3 with a K/D of 2.15

Kill Confirmed: The first thing i highly recommend, which you have probably heard 500 times, is kill confirmed. Each time you collect a tag you will gain 50exp aswell as 50exp per kill. I find it best to run around with a sub machine gun, silenced etc and workin on flanking the enemy and easily collecting all the tags! Another effective way to get easy EXP in this game mode is to plant a tac insertion in a building, poke round, get killed then just collect your tag ino people who get up to 15k exp a game. You will hear alot of people say, ' headquarters/domination is alot better for EXP' which those game lasts around 15 mins, you have to remember a single match of kill confirmed will last near enough half of the time of most game modes!

Specialist: Specialist perks are very effective for leveling quickly. basically with hardline on your kills will come along at 1,3,5 with each gaining 200exp+ then you can also earn a specialist bonus which gives you every perk, each other kill you get with the bonus on you will get double EXP! use perks that will be effective for you to gain kills if doing kill confirmed, i recommend using marathon somewhere.

Challenges: Challenges are also very effective for leveling which are not really thought about in previous call of duties. Each gun you like to use i recommend going to 500 kills total on each, i say 500 and not 1000, as at the start of a gun you get small bonuses for silly amounts of kills such as 25/75/250. You should also try to experiment with attachments as you can get good challenge exp for those! this is only weapon challenges there are hundreds more! Using the specialists perks there are also alot of 10000 exp ones which will come further into your prestige, such as 'Gaining Steady Aim 500 times using specialist' for every perk.

Double EXP: Everybody knows about this one, which i highly recommend you buy with your prestige tokens, if you have double exp doing all the methods i have mentioned above you will find your self ranking up in no time, using double exp i have gone from rank 1-60 in just the 2 hours of double exp!

This was just a quick guide i written up as i seen alot of posts asking about this, if you can think of any other better ways please let me know