Black clouds
Black clouds are heavy. As soon as you land on them, they will begin dropping down. Extra planning is required to deal with them. Check what is coming after the black cloud. Make sure to jump on it at the correct moment, when you can immediately jump off to safe clouds.
Movement
Plan your moves with the shark. Follow the shark's movement. At first, you will be far ahead of it. However it will eventually catch up. When its fin is directly under the cloud you are on, the shark will try to eat you. Time your jump to happen exactly when the shark jumps to eat you. Doing this will give you a few more seconds to plan your next move. There are times that you should wait for the clouds to position themselves in perfect location. Do not always hurry. Think quickly and act as soon as needed.