I play a shit ton of Wanted.  And I'm quite good at it.  Top 3 every game for sure.  I'm now level 38. 
 
I have some tips for you if you'd like.
  
1) Make sure you have different profiles for different situations.  I have 3 main ones that I use every match.  One Defensive for when you're at the top.  One mid-tier offensive/defensive for when you're ranked fourth or fifth.  As well as one Completely offensive for when you're at the bottom. Choose whatever perks/abilities you want that fit how you play those different styles.  But to win you will need to know how to play all 3 styles.  Trying to get a mass amount of kills while having 3 people chasing after you is not an easy thing to do. (If you want profile examples I'll give them just let me know).
 
2) If you don't have any pursuers, use that time effectively. I've found that being at the bottom for the majority of the match is the easiest way to win a game if someone isn't blowing absolutely everyone out of the water.  When you're at the bottom, you don't have any pursuers, so you don't have to worry about being killed.  It lets you set up good kills worth a shit load of points.  
 
3) Amount of kills don't matter. Amount of points does. I can't count the amount of games I've won where the 2nd/3rd place person has ended up with 3-5 more kills than me.  150/100 point kills are worth dick all, do not put yourself in to a chase after you opponent, ever.  And if you do, don't try too hard to catch him it's just a waste of time.  Even if your opponent is running around on rooftops just let him run his ass across the map and calm down.  I guarantee you'll find him again, and you just make yourself an easy target by running after him. 
 
4) Understand your abilities.  I don't understand why so many people use smoke bombs like firecrackers.  If you smoke a bunch of people, it will not give away your target.  Figure it out.   
 
5) Stuns are not reliable. It used to anger me at first how inconsistent stuns are but it is definitely understandable.  If someone is coming up on you incognito and you know it is a pursuer. Get your ass out of there.  Chances are he will chase you and give himself away giving you a chance to hide during a chase.  You can not rely on stuns or last minute smoke bombs.  Think about it in a real situation.  If someone sees you, and is that close to you, your smoke bomb/stun isn't going to do shit, they will still stab you. 
 
6) Don't spend the whole match on the rooftops. I don't care if you're basing your playstyle on a stupid arm cannon or what, the rooftop is only your friend for getaways and if it is convenient to go up quickly to get an aerial kill. 
 
7) Arm cannon kills are worth shit all for a reason. Ever seen someone use a damn arm cannon for 75% of their kills? They never win... 
 
8) Incognito is how you're supposed to kill people. Silent is good.  Incognito is better.  If possible, which it usually is.  Do not give yourself away in the least.  This way you can blend with the group they are blended with.  And get a full focus kill.  One Incognito kill with full focus is 550 points.  That shit is dope.  If it turns out you're on a roof, try for the incognito full focus, all of a sudden its 650. 
 
Thats all I can think of for now, and also, these are strictly Wanted tips.  I've played other game modes but do not like them other than Alliance, which I just play like Wanted anyways.  Hope it helps.    I'm thinking I might make some videos. 
 
Brought on by this thread.