Overcoming writers block in role play. (Or working on making your role play posts longer.)
A few things you could bear in mind when writing out responses to role plays;
What do they hear?
What do they see?
What do they taste? (if eating or on the air)
What do they smell?
What do certain things feel like?
This is a good way to beef up your posts and gives your character an opportunity to react or have thoughts to certain things mentioned in the previous post, no matter how small they may seem.
For example, your partner might have mentioned in their post that their character was fidgeting with something as they were talking. Does your character take notice of this? If so, what do they think about it? Do they merely notice and choose to ignore it or do they find it a little annoying? Or do they notice that the thing they're fidgeting with is unique in some way, such as a coin with special markings?
How does your character feel about certain things that happened as they happened? Angry? Upset? Terrified? Happy?
How did they express these emotions? Shaking out of fear? Lip quivering because they're about to cry? Cheeks turning red out of embarrassment? etc.
What are they thinking when each event occurs? Do certain events trigger memories that they could relive in that moment?
These are just a few ideas to help you out. They sound basic but you'd be surprised how easy it is to let a few of these slip when you start to feel creatively burned out. Hope they help :)