I do not debug a lot anymore since I like unit testing and it saves a lot of time. Having this said, I keep on forgetting shortcuts for debugging ... ok, also other things.

Therefore I created a small collection of useful Eclipse shortcuts.

Description  Shortcut 
Format source code.  Ctrl. + Shift + F 
Comment out a block of source code with one key combination.  Ctrl. + Shift + / 
Refactoring - Rename a variable. Alt. + Shift + R
Refactoring - call "Source" context menu for common refactorings like "Create getters and setters". Alt + Shift + S
Toggle a breakpoint Ctrl. + Shift + B 
Start Debugging / Run Application F11 
Go to definition / declaration. F3 
Open project properties. Alt + Return
Debugging - continue execution. F8
Debugging - Step into a single line of code. F5
Debugging - Step over a single line of code. F6
Call JavaDoc. F2
Jump up to next method header above current selection. Ctrl. + Shift + Arrow Up
Jump down to next method header below current selection. Ctrl. + Shift + Arrow Down
Move back to last position in any file. E.g. you jumped into a called method using F3 and now you want to go back to the calling method. Alt + Arrow Left
Move forward to a position in any file selected after the current position. Alt + Arrow Right
Switch between files in the editor pane. (Ctrl. + Picture up) or (Ctrl + Picture down)
Show a list of all opened files for filtering by file name and single selection. Ctrl. + E
Execute a single jUnit test case. Select Run As -> jUnit Test Case from context menu on a single unit test method.
Open or jump to view package explorer. Alt + Shift + Q, P
Move a whole line of source code up or down. (Alt + Arrow Up) Or (Alt + Arrow Down)
On line with warning or error like fix imports to enter specific context menu. F2
Jump to the Editor window. F12
Switch between views like from Editor back to Data Source Explorer or Package Explorer. Hold Ctrl. pressed even after pressing F7. Ctrl. + F7