Looking for some advice on how to properly communicate what I want (hookups).

(If I'm posting this in the wrong place/has already been asked, just remove my post and tell me to fuck off)

To add a background story, I got out of a long term relationship of 3 years about 6 months ago. My ex was my first everything, first kiss, first girl I lost my virginity to, etc, I just turned 24 for perspective. So needless to say I don't have a whole lot of experience compared to some.

I downloaded tinder about 3 months ago, and since then have gotten just under 700 matches, so I suppose I'm doing okay. The issue for me is how I approach tinder. I get asked for sex fairly often, and can set up dates without too much effort, but I still approach each situation with a blue pill mentality perhaps due to lack of experience. I've hooked up 4 times since being on there, and only because the girl asked to, yet every one pushed for a relationship hard afterwards, despite them clearly stating they were just looking for a hook up. I tried to give it a go with a few, which was obviously a big mistake and in the end I always get accused of being an asshole, etc.

So my question is to you guys, what are your techniques for clearly stating that you're looking for a hook up and nothing more, while keeping things pleasent and avoiding hostility.