Want to "undo" formatting options? 

If you just typed them, then click the "undo arrow" on the top left of the toolbar.

If you have a bunch of stuff to undo, do this:
Highlight the text you want to unformat, then click FORMATS ⇒ CLEAR FORMATTING

BTW:  The "alignment" option also works to align images in your text. First highlight the image, and then apply formatting.

An important note about a big change in what happens when you press your ENTER/RETURN KEY when creating a post....

In the old editor, when you tapped your ENTER/RETURN KEY at the end of a sentence, your cursor only moved down one line. 

In the new editor, when you tap Enter/Return, it double-spaces to start a new paragraph. 

This change trips up a lot of people. It's an old habit from typewriter days, and the early days of WORD when Enter = a Single Carriage Return. But even WORD in 2007 started making the Enter/Return key add a double space to start a new paragraph. Our new editor adheres to this evolved standard.

Tip:   If you just want to go down ONE LINE, then press SHIFT + ENTER.  That's a universal "go to the next line" key combination found across the web and in WORD as well. 

More Post-Editing Tips...

What the very handy PRE, DIV and BLOCKQUOTE options do.

(These options are found when you click Formats, then "Blocks" in the Editor.)

The "block" formatting options are things you can "do" to a block of text. 

The  Pre option turns your highlight text into "Mono-spaced PRE-formatted text."  This allows you to precisely align your texts to make a quick columns using your space bar or your Tab key.

Applying the  Div option to highlighted text un-does the pre-formatting.  ("Div" is the name of the html code which marks a "division or sector of text for formatting.)

See examples below.

Blockquote, indents the text block you have highlighted and puts a box around it.

Paragraph "un-does" blockquote, div, and pre-formatting, It's the equivalent of "return to normal."

PRE Example
See the perfectly aligned columns? That's because I applied the PRE option.

<pre>
Jack:   Hello. How are you?
Jill:   I'm great.  Thanks for asking.

Jack:   Column 1:     Column 2:
        1  2  3  4    5  6  7  8
                      
</pre>

Jack: Hello. How are you?
Jill: I'm great. Thanks for asking.

Jack: Column 1: Column 2:
1 2 3 4 5 6 7 8

For advanced posting and editing...

Our Post Reply window's toolbar supports the following common keyboard shortcuts to format highlighted text and do other things in the editing window.

ctrl + i = italics

ctrl + b = bold

ctrl + u = underline

ctrl + c = copy highlighted text

shift + end = highlights text from cursor to end of the line (good for sentence highlighting)

ctrl + k = insert link

ctrl + f =  opens find and replace window

ctrl + g = open simple 'find' field to locate a word or phrase on the page

ctrl + z = undo last thing you typed or formatted

ctrl + x = delete highlighted text

ctrl + v = paste from clipboard  (if you have a URL on your clipboard, you can also turn a highlighted text into a clickable link using ctrl + v)

ctrl + shift + v = paste as plain text from clipboard

ctrl + a = selects all text on page

ctrl  + s = saves the entire page  to your computer as an HTML page you can open offline.

ALT + SHIFT +  1,2, or 3  turns a highlighted text into Headline 1, 2, o 3 font size.

And my favorite...

shift + tab = jumps up to the toolbar!
                     great when typing long gpost so you don't have to scroll up to the toolbar

re: ALT + SHIFT +  1,2, or 3  turns a highlighted text into Heading 1, 2, o 3 font size.

Here's a reference of what the various "heading" font sizes will look like:

Heading 1 <h1>

Heading 2 <h2>

Heading 3 <h3>

Heading 4 95% of normal <h4>

Normal Text <p>normal</p>    The "paragraph" option is under "blocks" on the toolbar