Main parts of having a good post
1. Good And Clear Descriptions of your actions and setting: when you go to attack someone
Be specific by describing how strong the attack his and what type of attack you did
Ex: Sephirim Attempted a left foot Windmill kick aiming for john Henry's eyelid
make sure you state what your attacking with and what your aiming for, those are the to many parts of attacking your opponent, if you want to make it more fancy state how strong the attack was , so the other rpger would know how to take the attack (which could prevent less no selling. also state how you presented the attack, through a dash jump etc.
Now let me move on to Describing the settings, when your describe the setting , Describe most of the thing in your surrounding to make the match interesting and the post longer. Describe the air temperature,time of day, ground texture etc. this is one of the key elements to creating an excellent post..
Describing your setting should be the introduction to your post, you can use it later on in your post too, just dont recite the same thing over and over it will get repetitive.
2. make your post oraganized
If you are talking about the setting make a whole paragraph about settings, if you have a paragraph talking about Your characters thoughts then make a apragraph about that etc, basically donnot have alot of different subjects in one paragraph, the post will be short if you do that..
also bold the thoughts or statements your character make so the other rpger wont get confused
im only giving these two tips for now ill right more another time