Klaus has a ability to do more with flying with Violet's invention. Use Klaus for that to fly over things.
Levitating Loafers for Klaus:
At Uncle Monty's house you will need to make a pair of Levitating Loafers for Klaus. You will find one of the invention pieces, a pair of boots, outside the shed, above the door, in Uncle Monty's garden. In order to climb up and get the boots, you will need to use the Brilliant Bopper (or the Fruit Flinger) to knock over the water cans that hang from the second floor windows. The spilled water will cause giant flowers to grow. You can then jump on these to get over to the roof and grab the boots.
When climbing on the outside of Count Olaf's Tower, you usually go to the left to work your way up the tower. However, sometimes if you work your way to the right and peek around corners you might not normally look, you can find health lockets.