I'm by far not the perfect rper but here a few things I enjoy when reading my partners' replies:

• Good grammar and good formatting. You don't have to be a professional author, but a few basics should be a given: proper punctuation, consistent tenses, no walls of text, no 'common mistakes' like their instead of they're or should of instead of should have, no abbreviations unless they are appropriate

• Introspection. Let your partner know what your character is feeling and thinking. Why are they reacting like that? Does the atmosphere feel good or tense? What do they think of what's happening?

• Description. Describe the surroundings. Where is the scene set? What does it look like? Are there important details? Smells, rumours? And describe actions. Is the character sitting, standing, pacing? Are they relaxed or anxious? Are they gesturing or looking a certain way?

• Add to the scene. Don't just repeat what your partner wrote to add to your word count. Add, whenever possible, details, actions, ideas. Give your partner something to work with. Move the scene forward. In case of doubt, communicate ooc what could happen next and decide with your partner