Ill bite. The not-english-speaker thing is difficult and it depends on what country you are from so im ignoring that sorry. erp is actually just like any writing, try and read good books with *good* but fast-ish writing, so, more Terry Pratchett than Hemmingway, etc. The point is that as you read them you will pick up their writing voice and also be introduced to common idioms and phrasing (Pterry is great for this because he changes his phrasing for character accents), and if you read enough diverse stuff you will develop your own voice!
Now the trick I use to stop it getting boring with my partners is to do situational stuff and more importantly *BE DESCRIPTIVE*.
The key difference here is that erp rests on erotic visualisation, and you cannot effectively visualise something if it isnt described properly!! So visualising a coherent scenario here is super important. What I tend to do is imagine a specific scenario, and think of what i would want to do, and then pick out /details/.
So for example:
"I take off your shirt"
That's… it's bad, quite frankly. First of all, what are your bodies doing when you take off her shirt. How do you look at her, what do you feel emotionally and physically. You don't just lean down and lick her nipple, you touch her in other ways while doing that, you kiss and nip at the surrounding skin and listen to her gasp and moan while your thighs rub together, you feel her heat against yours and delight in the taste of her skin. There is *so* much detail here that could exist, but is lost. My technique is to focus on details and pick out the strongest ones, emotionally, and the most diverse ones (if you focus on breathing for a little bit, don't focus on breathing for a few more lines exchanged), and chain them together. It's also good to chain together two actions so it gives it an actionable flow, idk how to describe that in other terms so I hope you will just see what I mean :)
The last point is, all of that has to be balanced with speed! You're going to go slower as you start with this but try not to make her wait five plus minutes looking at the "x is typing", it's a real mood killer :/
So with that in mind, here is the improved version:
"I lean in closer to you, letting you taste the heat of my breath as our lips almost brush. As I move closer to you, I take you in my arms and move my hands down your sides, slowly taking your shirt over your head, before leaning in closer to lick and kiss your neck, moving gradually downwards to your chest"
Notice the primary goal here is to be /sensual/. You are creating an experience that both of you will hopefully moan and whimper too. Common sentence constructions I use are "As I …", and "xyz, before I abc" and things like that. It also helps if you remember a lot of synonyms, so for example changing "slowly" to "gradually" the second time I want to use it, because it's weird to read something with one adjective repeated a bunch of times.
The last point that I can't really convey is, if the text medium supports it, italics and bold.
Being told "You're such a good girl, aren't you?" personally is less of a turn on than being told "You're *such* a /good girl/, aren't you?". Again, you're trying to represent information that would be lost over text, which in this case is how you intone (intonate? hm) your voice!!
Anyhoo, this is how i sext my wives and lovers and how my wives sext with me (My one wife used the good girl thing with me and she introduced me to using italics and hnng it's real good and effective holy shit).
