If you have a dry sarcastic humor but have not found a way to translate this into text then I will try to explain.
DO'S
If you think people will misunderstand your sarcasm here are some things you can do to increase their saves on the sarcasm check.
1. Place a *sarcasm* text *sarcasm off* line in there
Utilizing this method anyone who mistakes your post for a serious one will be called out for their inattentiveness. In otherwords this is a no fail way to ensure people know you are being sarcastic. However, a good sarcastic comment is best made without this method. If you have to tell people you're being sarcastic it just doesn't go over as well.
2. Similarly you can use lots of types of emoticons
Again this is very much like telling them you're being sarcastic although there is a higher % chance they will fail their sarcasm check but these would all still be forum newbies or just generally people who don't read all of your post before commenting. A bonus to this method is that because you aren't coming out and saying THIS IS SARCASM the post is generally a higher quality.
3. include outrageous comments at the end
example: Drow is obviously the best choice for a barbarian and the world is flat.
There are some oft used phrases that you can fall back on (like "if you believe that then I have something to sell you"). Adding a phrase like this can be good (if your post was borderline sarcastic) or bad (if the sarcasm was apparent something like this probably isn't needed)
4. emphasize certain key words with bold lettering or misspelling
example Drow is obVi0uzly the best choice for a barbarian
There is a time and place for something like this. People like to do it with things like hjeal to immitate how often noobs misspell it when they're asking for a hjeal in combat. Sometimes this can help others get the jist of a sarcastic post.
5. utilize a tone that is not generally used in a forum post
Like you could totally tell that I'm posting this comment sarcastically because, like, I'm totally using valley girl style.
DO NOT'S
1. say something that a noob would consider to be a fair statement.
We have so many noobs on these forums (even some with join dates over a year). Sometimes you can spot them by their post count but other times you can't. Anyway, we get people all the time who come here with their outrageous comments and they're being serious. Example: We've all seen posts like this one "wizard should be a team player - some wizard joined my group and got more kills than me and I'm a barbarian. I just wanted him to cast hold so I could kill everything." Generally I try to ignore such comments if your forum join date is over a year old however, every once in awhile you get someone who is being serious with a comment like this.
2. try sarcasm in an otherwise serious post
There are ways to do this I guess but too often it comes out something like this example
example: I mostly like update 13. The quests are fun and I'm having a good time leveling up my TR thanks to the learning tome plus I love what they've done with the epic scroll drop rates.
Assuming the first part of the statement is true people will miss out on the sarcastic part of the statement. Or they'll take your whole post to be sarcastic. The best thing to do is to choose a tone for you post and stick it out all the way through.
Well that is all I have for now. If anyone can think of anything else feel free to add it below.