There's no easy way, it's the kind of game that's both a pain and great fun at the same time. The earlier ones are the worst, especially the first time you're in the forest. It gets easier as you increase Choco's beak level, but you can still spend a long time on it. As for strategy, well I find it best to develop a path through whatever area you're in and stick to that. When you get a kweeeh?! or kweeeehhh! I find it's best to try and create an idea of the perimeter, so try and gain an idea of where the treasure is by determining where the kweeeehhhh! switches to kweeeh?! You can create a spiral approach doing this, which tends to work. However there are always times when it takes forever, and often the best bet is to back off if it's taking more than 5 seconds in kweeeeeeh! territory, turn around and go right back - sometimes it's simply a matter of having Choco facing the right direction.
Finally, break the game up, so for example in the first disc you'll do the forest and then the lagoon (lagoon might be 2nd disc, can't be sure). Do the forest as soon as you can, then you can forget it until you gain the Blue Narciss, as there are only a certain number of chocographs you can dig up each time. Then you can gain mountain and ocean fairly quickly, and once you've done the forest for the second time it should be getting a lot easier. I tend to find that the first forest game can take me up to 90 minutes/2 hours to get the chocographs and chocograph pieces whereas the full lagoon game can be done in a third of that time. And the air garden is even easier.