I: stretch out the index finger of the right hand, and point to yourself;
Love: stretch out the thumb of the left hand, and the right hand gently touches the back of the finger of the left thumb with the palm;
You: stretch out the index finger of the right hand, and point to the each other;
But this is standard sign language, and there's a lot of it on TV and online, so I'm guessing almost most people know what it means.
I wonder if what you're referring to would be 'I like you' sign language:
me: right hand extends forefinger, point to yourself;
like: right hand thumb, forefinger slightly curved, as if pinched into a semicircle, fingertip towards the chin two times, at the same time the head downward slightly two times;
you : right hand extends the index finger, pointing to the other side;
this understanding of the people may be less oh!
There's also some Chinese 'local sign language': the word 'love', which involves synthesizing a heart with both hands; this one probably isn't what you want, because the meaning is too obvious, hehehe!
Also, I've attached an 'international sign language', which I've just taught to the international sign language class next door to mine:
Stretch out your right hand, with all five fingers naturally open; then bend your middle finger and ring finger (like the eunuchs in the TV series who used to do the "orchid finger" thing), and push it out forward to read, " I Love You".
That's all I can think of.