This is such an easy process and it takes less effort than you may think. I'll give you all the information I can about this. I always send all the supplies you need to root leaves in with my auctions. I send instructions as well. The only thing I don't send is the dirt. hehehe
The Soil
That leads me to this. The soil you use is very important to little leaves. Their roots are very tender and can be crushed easily by ordinary potting soil. It needs to be lightened up a bit. The best way to do this is to run to Wal-Mart and get some vermiculite, perlite, and potting soil. They are not expensive at all! They come in a bag like potting soil and can be found close by. I like Schultz and/or Miracle Grow. Both are good. You want to take a bag or box and put equal parts of each into it. Mix well and you're all done. This is the only part that takes a lot of time. Once you have a bunch mixed up (and well sealed up as not to dry out), you can keep it in a cool dry place. Oh, and try not to breath in any of the vermiculite dust.
Rooting Cups
Next, you'll take the rooting cups that I send you and with a marker, put the name of the leaf you'll put into it on the cup. It's so easy to lose track of their names. You want to do this right away so you don't forget. Next, put about 1 1/2 inches of soil mix into your cup. Then take a pencil or pen and push a little hole into the dirt. You want to use a pen or pencil instead of the stem because you can easily crush or break the stem by pushing it into the soil. Then set the cups aside.
Preparing Your Leaves For Rooting
Get your leaves. Take one at a time out of their bags. You'll notice that they are cut at an angle at the bottom. With a CLEAN and sharp knife, trim along that angle so the cut is fresh. You really only want about an inch or so of stem from the bottom of the leaf. Then just put the stem into the little hole in the dirt and carefully spread the dirt around it to keep it steady.
Water
I always water until the water runs out of the bottom of the cup for the first time. I use an old turkey baister to water my leaves. I can easily gauge how much water is coming out this way. Then, I place the cup into a small cup or dish and place on a window.
Sunlight
I don't give them full sun but bright, filtered sunlight. They can get sunburned easily and turn yellowish brown. NOT GOOD FOR BABY LEAVES. Next, it's important to remember to keep the soil damp but not soggy and never dry! Baby leaves don't have enough stored energy to survive without water and can rot if they sit in water all the time.
Fertilizer
Don't use fertilizer for a few months. It can burn the new roots and kill the leaf and babies. The soil should have enough food for a while anyway.
The First Sign Of Life
Well, after this is all done comes the waiting game. Waiting for the first sign of life. It can take anywhere from 3 weeks to 5-6 months. It really depends on the leaf. I once had a leaf rooting for almost a year and nothing was happening, not even roots! Well I just cut a fresh bottom on the stem and started over. I now have babies (but it took about 14 months to see anything). Like I said, it just depends. More than not you'll have babies in just a few weeks.
Replanting
You don't want to replant them until the baby leaves are bigger than your thumbnail or until you feel comfortable enough to handle them. I sometimes don't even separate them. I just repot the entire system of roots and babies into a 4inch pot. You can just do what you like here. Oh, and don't worry if the mother leaf dies after the babies push through. Sometimes that happens. But sometimes too you can cut off the mother leaf if it still looks healthy, and start all over and double your babies! You can get anywhere from 1-5+ new plants from 1 leaf.
Well I hope I didn't make your eyes fall out with all this writing. You can easily sum up the entire process. Dirt, holes, cut, plant, water, watch! If you ever need any help, PLEASE don't hesitate to ask me. I promise that next time I won't be so long winded