Navigating the pit of water at the end of room 1 can be tricky. Upspitting the monkey allows you to bounce off it and reduce fluttering. Most runners flutter over the first jumping fish as it jumps randomly and is difficult to react to. The last fish sometimes won't spawn, meaning you will have to do an extra flutter.
Spitting the monkey at the crab at :31 will sometimes kill it, but it may just stun it so it's easier to jump on without getting hit. The small left-right at :35 is not necessary but makes the section much easier.
At the start of room 3, a full jump (without fluttering) once Yoshi is past the longest vine should land you on the little piece of land in the water without collecting the red coin above. Try to end this level with 6 eggs as they will be useful in 3-8.