Be prepared to bore yourself senseless.
What I did was try to get either through either the WWE Tag Titles or the Hardcore championship line-ups. They were usually the 2nd or 3rd choice for me (it depends on who you pick, I think, but not by much). Doing so will unlock the Tables match.
Abuse the tables match for damn near every match, except Number one contender matches, in which you're stuck doing whatever match they want of you. But one match out of 5 or 6 ain't bad. And tables matches go by ridiculously quickly. Just earn the star amounts you need to move on, and do so. I always tried to 5 star my first match, 4 star the second, and then you can half ass the last two and the championship match.
It's tedious. It's boring. You can do it legit if you want, but I found this to be THE fastest way.
Also, if you want, you can knock out two more achievements. You can get the Gold Rush (all championships won) by starting a woman's career, winning the belt, saving, backing out, and restarting a career as a male. Then just play through EVERY week to get the A Year in the Life one as well, while making sure you win every belt possible. Then cement yourself as a legend.
When defending your belt, I'd avoid the WWE and World Heavyweight title line-ups. Hell, Unless you're going for the Gold Rush, I'd avoid those two altogether. I always stuck with the two tag lines, hardcore, ECW, US,and IC titles. Never failed me.
Well, that's it for me. Sorry to blabber on. :-p