Because the new Start menu takes up the whole screen, it's bound to be jarring. One way to get around this is to move the Start screen to a secondary monitor, if you have one; another way is to use the taskbar that much more.
Apps can be pinned to the taskbar and accessed with a single click, just as in Windows 7. To pin an app, right-click on it on the new Start screen and click Pin to Taskbar in the App bar that appears. (On a touchscreen, drag it to the bottom and then release.) Your average taskbar has space for quite a few apps, with Explorer and IE (which you can replace with the browser of your choice) pinned by default. You probably already do this with Windows 7 for commonly used apps, so there's all the more reason to continue this practice now that Microsoft has scuttled legacy Start.
Right-click on legacy Windows items on the Metro Start screen to pin them to the taskbar, as a way to avoid having to traverse the Start screen to launch them. The taskbar should have enough space on most systems for several commonly used applications. (Click for larger version.)
It may look like it has vanished, but type-to-search remains another useful way to avoid getting hung up on the Start screen. Type-to-search behaves roughly the same way as it does in Windows Vista and Windows 7: Begin typing, and you see results. (You do need a physical keyboard, so this technique won't work on a tablet with just an onscreen keyboard. Instead, open the Search charm by swiping from the right edge of the screen.)
Simply begin typing from the Start screen to start a systemwide search. Note that the context of the search is determined by the highlighted item directly below the search box. (Click for larger version.)
A major difference with Windows 8 is that results are visible only one category at a time, instead of showing the first three choices from each category, as is the case with Vista and Windows 7. In Windows 8, categories are listed beneath the search box. Just use the arrow keys or mouse to navigate between categories to reveal relevant results.
Triggering a search from within a Metro app by pressing Win-Q will automatically have the current app used as the context for the search. (Click for larger version.)