Clue Number 2 may be a little harder. It requires concentration and focus. It actually involves listening to what your other half is saying to you. At all times. It also involves reading between the lines. All talk of future plans will be redundant. Try booking a weekend break for a few weeks in the future? Nu uh, not gonna happen. Your soon to be ex will no longer ask your opinion on anything unless its along the topic of the new apartments just built on the other side of the city or the difficulty rating in getting mail.
Clue Number 3 is important, it involves sex. The sex will begin to wind down now, if it even still exists. When you do find it happening it may include some fantasy play involved you pretending to be someone else, anyone else, just not you. If your partner looks blankly at the roof, walls, anywhere but at you during sex, bad sign. But if they begin reading the day's mail or filling in crosswords while you are in flagrante delicto, forget it, it's over.
Also, try combining the listening clue with the sex clue. After sex, while still embracing use the words, "I love you." If he or she replies, "that's good," bad sign, if they have already rolled over and gone to sleep, that's worse. If they jump up, put on The Beautiful South at full volume, and then start ranting about how love has no meaning in the modern society, "look at Brad and Jennifer", then forget about subtle signs.
Of course all of these signs do not necessarily mean the relationship is over, but they should give you a pretty good idea that something is wrong. The best way to deal with it is to break the signs down into a time scale. Have the signs all happened in the last few months? If they have, the situation may not be irretrievable. If they have occurred within the space of the last 24 hours then your future together does look shaky to say the least. If you come home and find your home emptied of furniture, then the subtlety routine is over with.
And when it's all over, try and be dignified, it ended for a reason. You may be sniffling into your bowl of tear soup with the hope that he or she is feeling the same way and one phone call or text message won't hurt, don't. Remember when you ended relationships and were secretly glad that they were over? That may be how your partner is feeling right now. Plus they are probably telling their friends about all the signs they gave you that the relationship was ending. Sadly, you were just too dumb to pick up on them.