I'm rather surprised than no-one has so far mentioned backrolling. It is the best and the most difficult of the non-novelty spliff rolling methods. That said it is not as hard as it sounds or looks. I took me years to even attempt to use this method because it looked so hard. The first time I tried it it went off without a hitch though I could roll pretty well by that point.
Why would you spend the extra effort to backroll? Well, I personally liked to do it becasue it is the easiest way I have found to make perfect cones every time. It also only uses as much paper as is actually necessary. This results in two benfits. The first is that you smoke less paper, the joint tastes better. The second is that it reduces the canoe probability to almost zero (assuming uniform pot distribution) and does away with the nightmare scenario that happens when there is a little pocket of air between the two layers of paper in the joint and you light it only to have it burn down to the roach in about a second.
So how do you do it? The first thing it that you must be using one and only one paper. It is possible to backroll a construction of many papers but it is much more difficult. Take your paper and put it on a flat surface the wrong way up. The gum should be on the underside of the side closest to you. Reverse the crease of the paper.
If you are making a joint with pure weed then you can pretty much skip this section. Otherwise take you tobacco and make a thin mat that covers about three quarters of the width and length of the paper. Flatten the mat a little but not too much or it'll get too tight. Next sprinkle a line of hash along the middle of the tobacco. Now, when you roll it you'll get a nice even distribution of hash in the center which will help combat canoing.
Backrolling requires that you add the roach before you start to roll. I know this is a bit of a religious debate among stoners but it is pretty much a reqirement of backrolling. Sorry. It should also be noted that backrolling with a rolling mat or any other apparatus is not possible. If you can't roll without a mat you shouldn't be trying advanced joint rolling techniques anyway, but that's another node.
Add the roach. Pick up the paper and start to roll it between your fingers as usual. Now is the moment that backrolling really diverges from forewards rolling. When you are ready to make the tuck what you need to do is roll the joint all the way down so that the bit of the paper with the gum on it is facing you. Like so:
_____________________
| |
| |
| |
|---------------------|<--- Tobacco + hash
|_____________________|<--- Gummed paper in front of tobacco + hash
The best way I have found to do this bit is to put your finger about half way along the gum and hold it on the tobacco. While you hold is grab the roach with your other hand and fold the gum over it. When the paper is stable on the roach you can let go of the middle of the joint and smooth the paper upwards. The aim of this bit is to get the paper with the gum on it to be right next to the tobacco facing outwards with rest of the paper folded over on top of it. Some people naturally roll this way when forewards rolling. These people will find this technique very simple. The rest of us just have to practice.
You should now be holding your joint by the roach with it half way rolled up. Locate the area where the gum is underneath the outer layer of paper. Lick the ouiter layer so that the moisture passes through the outer paper to the gum and sticks the two together. Allow the gum to dry as usual.
Now you have a joint with a huge fin of spare paper. This is the paper you would have been smoking if you had forewards rolled. There are two ways to deal with this fin. The safest is to fold it back on to itself, moisten the crease and tear it off, carefully. The other way is to set fire to it and watch it flare. This is dangerous and could result in a hull breach!
sideways says that if you can reduce the risk of hull breach if you combine the two fin removal techniques: fold the fin back, moisten the base then set it on fire. I haven't tried this but it sounds good to me.
If you really want to show off you can go further: fold back, moisten and rip from the roach as described above but leave the fin hanging on by a thread. Light the fin at the bottom, it will flare up and as it does inhale so that the burning fin lights the joint. It takes a little practice to get the timing right but it's reasonably spectacular. I take no resposiblity for burnt clothing, carpets or faces when using these techniques.
Next errrm, SMOKE IT.