Here's a little bit on how I clone in soil.
This is a 10 day process for me that I have found great results with. Starting with day one I fill some Solo cups with my soil and wet it a little. I also go select my cuts from the plant. Cutting at a 45 degree angle and scrapping the back lower side a little until I see a little white. Then I drop the cuts into a cup of water for a couple minutes until I get all my cuts or whenever I am ready to plant them. I have kept clone cuts alive in cups of just plain water for quite a while before planting them. Anyways, once I am ready to plant the cut, I dip the very end of the stem in Clonex rooting gel and make sure I cover around a good inch or so from the bottom of them stem. Once I plant the stem, I take a plastic sandwich bag and cover the Solo completely then tape all the way around tightly. This is day #1. After this is all done, into the tent she goes. The rest I will give day to day all the way to day 10.
Day #
1) Cut, plant and prepare cup with clone
2) Smoke some flower, enjoy and repeat
3) Cut 1 top left or right corner to create a small hole top of plastic bag
4) Repeat Day 2
5) Repeat Day 2 & 4
6) Cut the opposite corner of plastic bag to create a small hole
7) Repeat Day 2, 4 & 5
8) Repeat Day 2, 4, 5 & 7
9) Open both holes in bag a little more then they are
10) Open holes even bigger then before
On the morning of day 11 I remove the plastic bag and 9 times out of 10 the clone has rooted. I used to have bad times cloning plants but ever since I started using this method, I have been able to clone very easily.