A straightforward level that does not require any particular egg count. An enemy can be used for an extended flutter, which gets Yoshi high enough to make it over the middle of the level, removing the need to take the slow beanstalk. Finally, an easy way to kill the pirahna plant at the end of the level is to fire a neutral eggshot (simply tapping A if your controls are set to hasty) just before running into it. In this level, collecting a flower and getting hit by an enemy will both trigger an information box, which will waste a little bit of time.
This is one of the more difficult 100% levels, even though it is the first one. Ideally, you can make the flutter up to the top area with only two flutters. Make sure to swallow the dayzee during the leg kicking animation of the flutter, or else you will go slower and need 3 flutters.
The cave section can be done several ways. Trihex does a backwards egg shot and proceeds to the right out of the cave. This almost always causes lag, and unless 2 stars are collected from the backwards egg shot, is slightly slower than turning around after shooting the final 3 red coins (this is obviously unbiased :P )
After the cave is a series of difficult egg shots. Make sure to listen for the flowers to ensure that you collected them.
Possibly the best way to spit the shyguy is with a little jump. This allows you to collect stars 20 through 25 from the star cloud without any of them despawning. Normally, you must wait or the cloud will only give you 1-3 stars.