I've been on far too many dates where the girl seems like she is having a lot of fun and is interested in your conversation, does not resist your heavy kino escalation, and regardless of whether you do a kiss/makeout close, the next day she either stops replying to texts or drops you the friendzone or "I don't think I have much time to date with my busy schedule and all, sorry!" line (which basically means she is not interested in you).

It's one thing to go on a date where you can just tell the full-blown passion is there or the other extreme, if there is zero chemistry, but it's these confusing in-between cases that really piss me off.

Experts have a list somewhere of these IOD (indicators of disinterest) or tips how to detect the disinterest from early on? I'm not talking about the obvious ones such as her asking to be taken home early or not wanting to drink as much with you, but the subtle clues I can proactively look for in order to not waste time?

Whatever you do, the only thing that counts is the end is how much you have escalated that night. The more you escalate and make her feel comfortable, the better you're off. If you can have sex with her on day one, she'll less likely flake the other day if you can make her feel the same.

Answering your question would require writing a book. Start getting to know more girls and approach more, experience will teach you more than anything.

Motivation! Thanks man, will do.

Good reply from Xoved. The trick is to escalate to sex as soon as possible without triggering "buyers remorse".

Once she has slept with you she doesn't want to feel like a slut so she post rationalises it that there must have been a connection/attraction otherwise she wouldn't have done it. It's a "tipping point" for her.