This is the most important thing to do when you have lost your lane.
How to do it?
Most important thing is, you have to deal as low damage as possible to the enemy minions. This does not mean you don't last hit at all. Deal the last hit when they are like 10-20 hp, this way you should be able to immobilise the enemy wave exactly where you want them to be. Preferably you should be freezing the lane just outside of your turret range for easier last hitting and easy escape into turret. Also, if the enemy minions are just outside turret range, tank some damage from them outside the turret range until your wave comes.
This requires a bit of practice, and it's not an easy thing to do. Precise timing when last hitting, etc requires practice and skills to achieve.
Once you've frozen the lane, just farm and farm until you have enough gold to come back into the game.
Another way to win back a lost lane is just to let the enemy take your tier 1 turret. Freezing lane at tier 2 turret is much easier and if by now the enemy started roaming, all the more better since you can freely farm. If they decided to stay in lane, ask for ganks - they're already overextending a lot, so a gank from the jungle usually won't go wrong unless they are both horribly fat. If they are horribly fat, hug tier 2 turret and just try to stall as long as possible, since diving a tier 2 turret before laning phase is over is equal to suicide. This method is especially effective on mid laners since while you let the enemy take your turret, you can roam other lanes to help as well.
There is another option, but this one's rather risky. Freeze your lane outside tier 1 turret, then ask for a 4 or 5-man gank. This will guarantee that they enemy laner will be killed or at least pressurised, as such, they won't try to engage on you every second they can. However, if your team makes a mistake, then it might also result in a free quadra or penta, which makes the situation from bad to un-salvagable.