Boundaries,
Well most of mine came out of reading 'Boundaries Before Marriage' (also called Boundaries in Dating), by Henry Cloud and John Townsend.
My boundaries extend beyond sexual ones. I believe that sometimes having the 'other' boundaries up first, can often make the temptations be reduced somewhat.
But you asked for specific sexual ones, so here goes:
1. B can not be too cuddly when I am being emotional. My rational thought tends to go out the window when I'm very teary, and I can slip into sin far more smoothly when I'm in a sad mood. He can hug me and brush my hair, but he MUST not kiss me, or let me kiss him. It may sound tough, but I know it's a struggling point for me.
2. I can no longer spend a lot of time lazing with him, either in his bedroom, or on the couch. An inactive body often steers you into filling it with sexual things. Sometimes we have devotions in his room before bed, so with that, I've had to ensure I stay off his bed, on the floor (a bean bag comes with me), and I leave immediately after the devotion happens. We've recently moved this activity to the lounge room, due to me finding myself falling asleep in there - SO NOT A GREAT IDEA!
3. Putting the other first. Both of us, in past relationships where sex came into the equation, found ourselves easily distracted from things we should be discussing, cos sex was so much fun and FAR easier than finding out about each others dreams, beliefs, behaviours, etc. Since we've been focussed on discovering more about each other emotionally, psychologically, relationally, etc, the temptation to have sex has decreased dramatically.
4. Realising the place sex has in a relationship biblically, and why it was put there. I had to go through the hard way to work out why sex was best after marriage, but I think you can still work this out WITHOUT having done it. Reading really great books like the aforementioned 'boundaries' or 'Kissed the girls and made them cry' helped me out immensely with working this out for myself.
Anyway, yeah, there's my basics. Of course then we go into no spooning, no kisses below the neck, no falling asleep together (it's amazing what happens when you're virtually asleep and have been dealing with the temptation just before bedtime!), no graphic sex things like oral, fondling, simulations, etc etc.
Sasch