Rope tricks rely on the illusion you give to your audience that you're doing something to the ropes when you're really doing something else. You need to be deft with your hands and to practice your tricks you have mastered it. You should also try to find videos of this trick being done.
Here is one classic rope trick that never fails to amaze children and adults alike. It's called the 'cut and restored' trick. Basically what you will tell the audience is that you 'cut' a rope into two pieces, say your magic words and 'restore' it back to one piece looking as if it wasn't cut in the first place. It will sound impossible and because of that, finishing the trick efficiently will result in more applause.
You will need sharp scissors for cutting the rope. The rope should be about 2 meters in length. You might also need to practice what you will say while doing your trick. Sometimes that will help you distract the audience more than the trick itself.
Show your audience your rope. Start telling your story while passing it around. Tell a few jokes perhaps to get things started. Then double up your rope and then triple it. You will end up holding three sections of the rope. If you could come up with some story for that too, then do that.
You should do a cat-shank knot on each end. If you don't know how to do this, just put one end of the rope through the larger loop and then around itself and put it down through the small loop that resulted with what you've done. Try practicing this bit at home as it is the most important part of the trick.
Tighten the knots in place and show to the audience that you have divided the rope into three sections. Tell them your story again. Just make them laugh while preparing the most anticipated part of the trick. Now you can tell them that you will cut the rope.
Now here is where the illusion starts. Yes, you will cut the rope but what you're cutting is the small section of the rope with the knot at the end. This will result to 2 new ends. Grasp this two ends and pull the rope tightly between your two hands. The knots will stay in place if you managed to remember to tighten the knots earlier.
If you have done this correctly, your audience will just think that you've cut the rope and is eagerly waiting for your next move both because they think it's impossible to make or probably skeptical that you can do it.
Say to your audience now that you're going to repair your rope. While grasping with both of your hand, you will now cover your left hand with your right hand and slide your hand from end of the rope to the other end. You will notice here that as you slide along the rope, the knots will slide easily with your hand. The remaining trick to do is hiding the knots in an unseen way. You could do this by either pocketing it or letting it drop to the floor if you're hidden behind something, preferably a table.
Remember that part of the illusion in this trick is the story you are going to tell. Once you have your audience enchanted by your story, you will have an easier way to complete your trick. This is one of the traits of a good magician, to be able to tell a story while doing a trick.
Another tip is to research more variations of this trick. This trick has been done for a long time now that most people will find it boring. One advantage of that dilemma is that you will find out that other magicians have found different ways to do this trick. What you need to do is inject more life to the old ways to make your trick seem original in their eyes. This could also be helpful if your audience asked for you to repeat that trick in the hope of catching how you do it. You just show them a different variation and the secret of the trick remains.