We all know how dry a large block of black text on a white background can be. Especially the really long ones. Now, there are several things you can do to help your posts pop and even clearly define if your character is thinking, speaking, using telepathy, and so on. The main purpose of doing this is to break up the long line of chatter and turn it into something attractive to the eye.

Italics

These are great for implying emphasis when your character is speaking or show that your character is thinking. More on how to make the distinction later.

Example
'I can't believe that Gir is so insane!' thinks Zim.


Bold

Bolding your text is a great way to draw the eye to something you wish for people to notice off the bat. I suggest that you use it sparingly and only for spoken words. Combined with Italics and you can imply the character is emphasizing a word or words for effect - be it sarcasm or increasing the focal point of their words.

Example
"I can't believe you are such an idiot!"


See what it does there? It is clearly showing the person feels very strongly believes the subject in question is very stupid.

Example
"What?! You have got to be kidding!"


Here they are stressing their incredulous reaction.

Underline

Another way of indicating directing a strong stress on that particular word.

Example
"Why are you so stupid?" Ralph asks with exasperation. He simply cannot understand how anybody could be so completely stupid and yet so capable of pulling off impossible things.


Colored Text

Color is a great way to make a splash and help you keep track of which character said what. It is also a great way of adding some personality to your posts. There are many possibilities for how you use it. Ultimately, in the end, it makes it even easier to read. Just be aware that using paler colors will require people to highlight your posts just to read it. White text is also an excellent way of censoring information you wish to share, but not be blatant about - such as actions that could be considered a tad bit edgy or is a spoiler. It really depends on you.

Colors of text, Rainbow order
pink, lightpink, palevioletred, hotpink, deeppink, red, tomato, crimson, firebrick, indianred

darkred, maroon, brown, sienna, saddlebrown, rosybrown, tan, darkkhaki, BurlyWood, chocolate, peru, darkgoldenrod

lightcoral, coral, lightsalmon, salmon, darksalmon,
orangered, darkorange, orange, sandybrown, goldenrod, khaki, gold, yellow

greenyellow, lightgreen, lawngreen, chartreuse, lime, springgreen, mediumspringgreen,
limegreen, green, forestgreen, darkgreen,
seagreen, mediumseagreen, darkseagreen,
olive, olivedrab, darkolivegreen

azure, aliceblue, lightcyan, paleturquoise, lightblue, lightsteelblue, powderblue, cyan, aqua, aquamarine, turquoise, lightskyblue, skyblue, mediumaquamarine,
mediumturquoise, darkturquoise, deepskyblue, cadetblue, cornflowerblue, steelblue, slateblue, mediumslateblue,royalblue, dodgerblue, lightseagreen, teal,darkcyan, blue, mediumblue,darkslateblue, navy, darkblue, midnightblue

indigo, blueviolet, mediumpurple, mediumorchid, purple, darkmagenta, darkviolet, darkorchid, lavender, thistle, plum, violet, orchid, magenta, fuchsia, mediumvioletred


darkslategray, dimgray, gray, slategray, darkgray, silver


Note, I did not make this list of colors but am rather posting what somebody else posted in the guild so that I and my friends have a font color reference chart.


Quotation marks, Parenthesis, and Brackets

' - Quote " - Double Quote [ ] { } < > - brackets ( ) -Parenthesis

How you use these can indicate a tone or just be a matter of personal preference. In America for example, we tend to use the single quote for thought or to indicate you are quoting something, and the Double Quotes for spoken word. In Britain, however, that might not be the case. It's a subtle difference. This is why indicating with bold and italics can make a big difference. The brackets are more liberally used depending on your own personal preference, however, but I suggest you use consistency for what you are trying to imply.