Reading back through their pesterlogs is one of the best ways to gather a good grasp on how the character you are eye balling behaves. Research is particularly necessary in regards to fantrolls or bloodswapped characters.
I’d also suggest reading their designated page on the Homestuck wiki. I won’t go into too much detail on these since there essays discussing them at length that have been posted previously.
Tumblr or Livejournal will be better choices given their much more visual nature will give you the greater ability to clearly relay who and what it is you are attempting to roleplay.
Research Research Research: One of the best things you can and should do is research the character you are being thoroughly.
Where can roleplay Homestuck characters and find other Homestuck roleplayers?I also say to do this to avoid falling victim to spoilers if you are not caught up.It makes things a lot simpler for you and your partner as well as opening more doors for you to explore and play with. Start off with the friendlier and more jovial characters like John, Jade, Jane, Nepeta, Tavros, and Feferi just to name a few.What I suggest doing is preparing a good opening line that either states who your are or leaves obvious hints. I’ll go through those and the other activities one may do while roleplaying on Tumblr in sections.As a last resort you may just have to tell them ooc. Styles: Narrative style: Similar to writing prose and can be written from any point of view except first.