If you do not have a friend with the game and have to do the achievment alone, I would recommend the graffiti mode. It means that every obstacle is marked with a colour belonging to the rider, who scored the most points on it.
Get into multiplayer and host the map you are most comfortable with, one of the bigger ones are actually easier in my experience. If you are good in that game, some big combos with multiple grinds, manuals and airs might be enough, but in graffiti mode it is all about the amount of obstacles you own, even if you did only something like a kickflick 360.
So what you want to do is to look for ramps, rails etc. that are not too obvious and get them. Small quarter pipes without obvious gaps or short ledges are ideal. "Hidden ares" you have to jump/grind to are also good. Neverthelesse, stringing combos together obviously helps.
I would stay away from maps like warehouse or hangar, because almost everybody knows, what (s)he has to do on those ones. Venice Beach would be a good map, because it is easy for an unexperience oppent to waste 60 seconds while riding through the map without a plan. Another good one could be the mall and going for obstacles away from the straight donewards path.