For some users, using the mouse and keyboard is the most effective means of making corrections. This does not apply to those of you who have no use of your hands -- you should skip the following.
Even the "keyboard impaired" can learn to use a few keys. The numeric "-" key is, by default (you can change the key in Tools/Options/HotKeys) a key that is equivalent to saying "Correct That". Pressing the key is more reliable than saying "Correct That"! This can make going into the correction menu more reliable and thus less tedious.
The mouse is great for highlighting words, phrases, etc. Use it! You can highlight areas then hit the numeric "-" key to make corrections. Just be certain that if you do this, you are making the correction to match what you said -- not what you wish you had said. For verification/clarification you can click the "Playback" button in the correction box.
Note: Users of the Philips SpeechMike Pro should have a button on the SpeechMike Pro set up as a "correction" button to use instead of the numeric"-" key.
If you want to CHANGE text, highlight it, then re-dictate -- do NOT go into the correction menu.
Once in the correction menu, persons with reasonable typing skills may find entering correct words faster by keyboard than by voice. For some people, dictating letters of the alphabet is full of errors to the point of being counter-productive. Before resorting to the keyboard, try spelling the words quickly--Dragon seems to work better when it can work on several letters at a time instead of one letter at a time. Use the backspace, delete, and arrow keys to properly position the cursor within the correction window for insertions. I often use the backspace key to wipe out all that is wrong with a phrase, then add the correct elements via keyboard.
Your goal is often to produce the document in the most efficient manner -- use ALL the tools available to you. Most of your benefit of using speech recognition comes from using it for the initial dictation, not from editing the text using speech.